UC-NRLF 


llllill 


B   M   43D   DMl 


<9 


<^^- 


aoscience  &  NaAl 
Resourcasl^ibrary 


( rti)   "-■■ 


^o 


%. 


%. 


% 


^^ 


\  ® 


<?f. 


c©  X  (ft 


V 


M' 


'^. 


,^*''  (MlM^ 


.#• 


..^*'  <^ 


->*"" 


V/' 


t 


f  4 


t 

p 


>>4 


t 


PHARMACEUTIC  CHEMISTRY 


STANISLAUS 


A  SHORT 
PHARMACEUTIC  CHEMISTRY 

INORGANIC  AND  ORGANIC 


I.  V.  STANLEY  STANISLAUS,  M.  S.,  PHAR.  D. 

w 

Projessor   of   Pharmacy   and   Organic   Chemistry   and 

Dean  oj  the  School  of  Pharmacy  of  the  Medico- 

Chirurgical  College  of  Philadelphia 


CHARLES  H.  KIMBERLY,  B.S.,  (in  Pharmacy)  PH.  D., 

Professor    oj    Applied    Chemistry    in    the    School    of 

Pharmaceutic    Chemistry    of    the    Medico- 

Chirurgical  College  of  Philadelphia 


SECOND  EDITION 


PHILADELPHIA 

P.  BLAKISTON'S  SON  &  COMPANY 

1012  WALNUT  STREET 
1908 


^f*f/i^i 


Copyright,  1908,  by  I.  V.  St.\nley  Stanislaus. 

''Authority  to  use  for  comment  the  Pharmacopceia  of  the  United 
States  of  America  Eighth  Decennial  Revision,  in  this  volume,  has 
been  granted  by  the  Board  of  Trustees  of  the  United  States 
Pharmacopoeial  Convention,  which  Board  of  Trustees  is  in  no  way 
responsible  for  the  accuracy  of  any  translations  of  the  official 
weights  and  measures  or  for  any  statements  as  to  strength  of 
official  preparations." 


Printed  by 

The  Ma  fie  Press 

York,  Pa 


ERRATA. 


69. 

-Line  11: 

69. 

—Line  12: 

69.- 

—Line  25: 

73-- 

—Line    3: 

74-- 

— Line    7 : 

74- 

—Line  22: 

at  25° 

75-- 

—Line    2: 

87.- 

—Line  14: 

-Under    OXYGEN    read — "A    gaseous   element. 
Symbol  O.     Atomic  Weight  16.     Valence  2." 
"  1.52  "  should  be  "  1.403". 
"86°  C."  should  be  "  120.5°  C" 
Omit  "H— HCN". 
"  1.83  "  should'  be  "  1.826." 
"AsOj"  should  be  "AszO,". 
"1.71   at   15°  C."     should   be   "1.707 

"At  15°  C."  should  be  "at  25°  C." 
"Argenti    nitras    dilutus"    should   be 
"  argenti  nitras  mitigatus." 
113. — Line  10:     "Ferri     sulfas"      should     be     'ferri 

sulphas." 
113. — Line  18:     "Ferri    sulfas   exsiccatus "    should    be 

'ferri  sulphas  exsiccatus." 
113. — Line  22:     "Ferri    sulfas   granulatus"  should  be 
"ferri  sulphas  granulatus." 

"37.8%"  should  be  "29%". 

"62.9%"  should  be  "42.8%". 

"60%"  should  be  "55%". 

"  198.3  "  should  be  "  198.5  ". 

"  198.3  "  should  be  "  198.5  ". 

"40°    to    70°    C."    should    be    "45° 


80°  C."  should  be  "57.2°C." 
34.6°  C."  should  be  "35.5°  C." 
500  parts"  should  be  "360  parts." 
115°  C."  should  be  "  113°  C." 
170°   to   185°   C."    should  be    "155° 


114. 

— Line  21 

114. 

—Line  22: 

137- 

—Line  26: 

178. 

-Line    8: 

178. 

—Line  14: 

223. 

—Line  13: 

to  60°  C 

223. 

—Line  20 

317-- 

—Line    8 

343- 

—Line  13 

437-- 

—Line    3 

547-- 

—Line  18 

to  165 

°C 

.otfiSEl^ 


>^. 


TO    THE   MEMORY 

OF 
THE    VENERABLE 

ALBERT  ETHELBERT  EBERT,  Ph.  M.,  Ph.  D-., 

THE    NESTOR    AND    CHAMPION 

OF 

AMERICAN    PHARMACY 

THIS  MODEST  VOLUME  IS  RESPECTFULLY  DEDICATED 

BY 

THE    AUTHORS. 


192868 


PREFACE  TO  THE  SECOND  EDITION. 


Eleven  years  have  elapsed  since  the  printing  of  the 
first  edition,  and  so  much  progress  has  been  made  in 
the  science  of  chemistry  in  the  last  decade  that  the 
manual  had  to  be  entirely  rewritten.  In  revising  the 
work,  the  author  sought  the  aid  of  Professor  Charles 
H.  Kimberly,  who  has  brought  up  to  date  the  Inor- 
ganic part. 

This  book  has  been  written  for  students  of  Phar- 
macy and  prepared  mainly  from  the  hectographed 
lecture  and  laboratory  notes  which  have  been  periodi- 
cally distributed  to  our  students. 

When  only  a  limited  period  of  time  is  devoted  to 
the  study  of  chemistry,  as  is  customary  in  pharmaceu- 
tic schools,  it  is,  in  the  opinion  of  the  authors,  un- 
wise to  burden  the  student's  mind  with  details  of 
little  bearing  on  Pharmacy.  With  this  in  view, 
they  have  based  the  text  upon  the  United  States 
Pharmacopoeia.  In  no  way,  however,  is  the  book 
designed  to  usurp  the  place  of  the  national  standard, 
to  which  it  is  intended  as  an  introduction. 

In  the  first  chapters  the  elementary  principles,  such 
as  definitions,  nomenclature,  notation,  etc.,  are  ex- 
plained, followed  by  a  discussion  of  the  nonmetals. 
The  next  few  chapters  are  devoted  to  the  metals  and 
their  inorganic  compounds,  equation  writing,  stoichi- 
ometry,  "periodic  classification,"  etc. 
vii 


Viii  PREFACE    TO    THE    SECOND    EDITION. 

The  second  ])art  of  the  l)ook  is  devoted  to  Organic 
Chemistry  in  which  the  classification  and  sequence 
are  based  on  the  excellent  lectures  of  Professor  Daniel 
C.  Mangan.  In  this  portion,  the  needs  of  pharma- 
ceutic students  have  been  kept  constantly  in  view  and 
all  of  the  important  "newer  remedies"  discussed 
with  regard  to  their  derivation  and  synthesis.  Class 
reactions,  syntheses  and  properties  of  entire  classes 
are  given  wherever  possible.  The  articles  on  ele- 
mentary analysis,  deduction  of  molecular  formulas 
and  toxicology,  while  brief,  are  complete. 

The  final  e  is  dropped  from  the  names  of  the  halo- 
gens and  binary  compounds  and  organic  compounds, 
but  retained  in  the  case  of  the  alkaloids,  and  an  ar- 
bitrary classification  of  the  inorganic  compounds  into 
analytic  groups  has  been  attempted. 

It  is  hoped  that  the  book  will  take  the  place  of  the 
often  incomplete  and  inaccurate  lecture-room  notes. 

The  thanks  of  the  authors  are  due  to  Mr.  Joseph 
L.  Turner,  who  read  the  proofs  of  the  organic  part, 
to  Miss  Mary  White  Hutchinson,  who  has  rendered 
valuable  assistance  in  the  preparation  of  the  manu- 
script, and  they  wish  to  especially  express  their  thanks 
to  Professor  George  H.  Meeker  for  his  words  of  en- 
couragement and  for  kindly  ])lacing  at  their  dis])osal 
his  valual>le  notes. 

I.  V.  s.  s. 
C.   H.   K. 

Philadelphia,  November,  1908. 


TABLE  OF  CONTENTS. 


PART  I. 

Page 

Inorganic  Chemistry  Discussion, i 

Classification  of  Compounds, 15 

The  Nonmetals, 18 

Water,  Discussion  of, 48 

The  Atmosphere, 61 

The  Inorganic  Acids, 67 

The  Metals  and  their  Compounds, 7^ 

Ionic  Theory,  Physical  and  Electro-Chemistry, 178 

Chemical  Nomenclature,  Formulas  and  Definitions,     .    .  182 

Equation-writing, 187 

Stoichiometr}-, 196 

PART  11. 

Organic  Chemistry,  Discussion  of, 201 

Compounds  of  Carbon, 215 

Purification  of  Organic  Compounds, 558 

Separation    of    Organic     Substances    with     Immiscible 

Solvents,, 559 

Qualitative  Tests  for  Elements  in  Organic  Compounds,  .  561 
Elementary     Organic      Analysis      and      Deduction     of 

Formulas, 5^3 

Volumetric  Analysis,  Elementary  Discussion, 566 

Determination  of  Molecular  Weight, 57 ^ 

Toxicology,  Elementary  Discussion, 577 

Index, 59^ 

ix 


OF   THE 

UNIVERSITY 

OF 


PHARMACEUTIC    CHEMISTRY 


PART  I. 

INORGANIC  CHEMISTRY. 
CHAPTER  I. 

MATTER. 

The  science  of  chemistry  has  been  advanced  so 
rapidly  in  recent  years  that  it  is  almost  impossible 
to  keep  pace  with  its  progress.  For  this  reason  it 
has  been  divided  into  branches,  each  of  which  em- 
braces or  covers  a  special  line  of  human  endeavor. 
Thus,  we  have  "Agricultural  Chemistry,"  which 
deals  with  the  problems  of  successful  farming; 
"Metallurgical  Chemistry,"  which  deals  especially 
with  metals,  their  analysis  and  application  in  the 
arts.  Why,  therefore,  should  we  not  have  "Phar- 
maceutic Chemistry,"  dealing  with  the  chemistry 
of  medc'nes. 

It  is  justly  held  by  some  that  "Chemistry  is  no  less 
the  same  science,  whether  applied  to  metallurgy, 
medicine  or  pharmacy."  But  that  after  mastering 
the  underlying  principles,  a  certain  branch  of  it 
should  be  specialized  in,  no  one  will  deny. 


2  I'lTARMACEUTIC    CHEMISTRY. 

GENERAL  CONSIDERATIONS  AND 
DEFINITIONS. 

MATTER  is  that  substance  of  which  all  bodies  are 
composed.  Thus,  earth,  wood,  air,  water,  iron,  gold, 
etc.,  are  matter,  though  differing  from  one  another 
in  their  properties. 

Matter  exists  in  three  states  oj  aggregation:  (i) 
solids;  (2)  liquids;  (3)  gases. 

Matter  is  impenetrable  and  indestructible.  Ac- 
cording to  subdivision  (size),  it  is  divided  into 
^^ masses,'"  ^^ molecules'"  and  "atoms." 

Any  distinct  portion  of  matter  appreciable  to  the 
senses  is  called  a  mass. 

The  smallest  portion  of  matter  which  can  exist  by 
itself  and  retain  its  peculiar  characteristics  is  called 
a  molecule  (little  mass). 

The  smallest  particle  of  matter  into  which  mole- 
cules can  be  divided  is  called  an  atom   (not  cut). 

Atoms  are  hypothetical  bodies,  supposedly  indi- 
visible solids,  with  a  definite,  unchangeable  weight 
and  possessing  a  definite  amount  of  attraction  .for 
other  atoms  which  they  neutralize  and  with  which 
they  unite. 

An  atom  cannot  exist  by  itself,  but  it  unites  with 
other  atoms  of  the  same  kind  to  form  molecules. 
Molecules,  likewise,  unite  with  other  molecules  to 
form  masses. 

When  molecules  of  similar  c()m])t)siti()n  are  at- 
tracted to  each  olluT,  flie  force  causing  such 
attraction   is   termed  roliesioii;  when,   liowever,   (he 


CONTINUITY   OF    MATTER.  3 

molecules  are  of  unlike  composition  the  force  is 
called  adhesion. 

Atoms  attract  each  other  by  a  force  known  as 
chemism  or  cliemical  affinity. 

CONTINUITY  OF  MATTER.— ^^■hen  a  bar  of  iron 
is  heated  it  expands;  when  cooled  it  contracts.  The 
following  reason  for  this  change  is  given:  It  is 
assumed  that  the  metal  is  composed  of  minute  par- 
ticles of  matter  which  are  not  in  absolute  contact  and 
which  recede  from  each  other  upon  the  application 
of  heat  or  approach  each  other  when  heat  is  with- 
drawn. That  matter  is  not  continuous  can  further 
be  proven  by  the  fact  that  when  liquids  of  different 
densities  are  mixed  (as,  for  example,  alcohol  and 
water)  the  bulk  of  the  mixture  contracts  (shrinks). 
Thus,  if  100  cubic  centimeters  of  alcohol  were  mixed 
with  100  cubic  centimeters  of  water,  instead  of  hav- 
ing 200  cubic  centimeters,  as  one  would  suppose, 
the  mixture  measures  but  194  cubic  centimeters. 
The  loss  in  volume  (bulk)  of  6  cubic  centimeters,  or 
3  per  cent.,  shows  clearly  that  between  the  particles 
of  one  of  the  liquids  there  must  be  open  spaces  which 
particles  of  the  other  liquid  enter  and  thus  cause  the 
shrinkage. 

There  are  many  other  proofs  that  matter  is  not 
continuous,  but  the  above  two  familiar  examples 
will,  it  is  thought,  suffice  to  show  that  matter  is  com- 
posed of  exceedingly  small  particles  which  are  not 
rigidly  joined  together,  but  which  exist  at  some  mi- 
nute distances  apart  from  one  another;  and,  further, 
that  these  particles  are  in  a  state  of  constant  motion 


4  PHARMACEUTIC    CHEMISTRY. 

(vibration)  which  is  increased  by  raising,  and  de- 
creased by  lowering  the  temperature  of  the  substance. 
The  minute  particles  referred  to  are  called  molecules, 
which  we  have  already  defined. 

Since  all  compounds  are  made  up  of  two  or  more 
substances  into  which  they  may  be  split,  it  follows 
that  molecules  must  consist  of  smaller  particles. 
Thus,  if  a  molecule  of  hydrochloric  acid  be  separ- 
ated into  its  elements,  we  obtain  a  particle  each  of 
hydrogen  and  of  chlorin — these  smaller  particles 
being  the  atoms  referred  to  above. 

Molecules  of  compounds  may  consist  of  any  num- 
ber of  atoms;  molecules  of  elements  consist  usually 
of  only  two  atoms. 

ELEMENTARY  AND  COMPOUND  MATTER.— 
Matter  may  be  either  (i)  simple  or  (2)  compound. 

When  consisting  of  only  one  kind  of  elementary 
substance,  as  iron,  copper,  carbon,  oxygen,  etc., 
it  is  simple  matter. 

Compound  matter  consists  of  two  or  more  kinds 
of  matter  in  combination,  as  water,  which  consists 
of  hydrogen  and  oxygen;  or  iron  sulfate,  which  con- 
sists of  iron,  sulfur  and  oxygen,  etc.,  and  which  are, 
therefore,  compounds. 

Simple  matter — because  it  cannot  be  reduced  with 
the  means  at  our  disi)osal  to  anything  simpler — is 
called  elementary  matter  or  an  element.  .An  clement, 
therefore,  it  is  assumed,  consists  of  but  one  kind  of 
matter. 

About  eighty  kinds  of  clemenlar\  mailer  or  ele- 
ments are  known,  and  it  is  reasonable  to  suppose 


PHYSICAL    SCIENCE.  5 

that  others  remain  to  be  discovered.  Of  these 
elementary  substances  combined  in  different  pro- 
portion every  kind  of  matter  is  composed.  Indeed, 
the  entire  universe  is  constructed  of  elementary 
matter.  Many  of  the  compounds  discovered  in 
nature  have  been  reproduced  or  duplicated  in  the 
chemist's  laboratory  and  the  list  of  compounds 
is  constantly  increasing. 

SOLIDS,  LIQUIDS  AND  GASES.— It  has  been 
stated  above  that  matter  exists  in  three  forms.  Any 
one  of  these  three  forms  of  matter  can  be  converted 
into  either  of  the  other  two.  For  example,  ice  is  a 
solid,  but  when  melted  it  becomes  liquid  (water). 
By  boiling  the  liquid  water,  a  gaseous  vapor  or  steam 
is  produced.  All  matter  is  influenced  by  two  phy- 
sical forces,  the  force  of  attraction  (cohesion)  and 
the  force  of  repulsion,  and  according  to  the  pre- 
dominance of  either  of  the  forces,  the  different  forms 
of  matter  result.  Thus,  when  the  force  of  attraction 
is  greater,  solids  result;  when  the  force  of  repulsion 
equals  the  force  of  attraction,  we  have  liquids;  when, 
however,  the  force  of  repulsion  is  greater  than  that 
of  attraction,  gases  result. 

PHYSICAL  SCIENCE.— We  cannot  create  or 
destroy  matter,  we  can  only  alter  its  form  and  arrange 
differently  the  particles  of  which  it  is  composed. 
We  can,  however,  by  study  understand  the  changes 
which  are  taking  place  in  nature. 

The  study  of  these  changes  in  all  their  many  forms 
is  called  ^^ Physical  Science." 

PHYSICS  is  a  branch  of   physical  science  which 


6  PHARMACEUTIC    CHEMISTRY. 

treats  of  the  phenomena  of  matter  as  such,  without 
regard  to  its  composition. 

CHEMISTRY  is  the  science  which  treats  of  the 
composition  of  bodies  and  the  changes  which  this 
composition  may  undergo.  Since  chemistry  reveals 
to  us  the  secrets  of  the  hidden  particles,  the  term 
is  thought  to  have  its  derivation  in  the  Arabic  word 
meaning  "to  conceal"  (kamai). 

Physics  and  chemistry  are  very  closely  allied,  since 
nearly  all  chemical  changes  are  accompanied  by 
physical  changes,  and  many  physical  changes  in- 
volve chemical  changes  as  well. 

PHYSICAL  AND  CHEMICAL  CHANGES.— A 
physical  change  is  one  in  which  the  composition  and 
properties  of  a  substance  are  not  permanently  altered. 
A  chemical  change  is  one  in  which  both  the  composi- 
tion and  properties  of  a  substance  are  permanently 
altered  and  one  or  more  new  substances  produced. 

To  illustrate  these  changes,  we  can  take  ordinary 
salt — sodium  chlorid  :  It  is  a  solid,  but  when  placed 
in  water  it  dissolves,  losing  its  solid  form.  If  we 
evaporate  the  water  we  obtain  the  salt  in  its  original 
form,  hence  no  permanent  change  took  place.  Such 
a  change  is  called  a  physical  change.  If,  however, 
we  place  the  salt  in  sulfuric  acid,  while  it  again  dis- 
solves, on  evaporation  an  entirely  different  compound 
results.  A  permanent  change  has  taken  place  and  a 
new  compound  j^ossessing  different  properties  has 
been  formed.  Such  a  change  is  known  as  a  chemi- 
cal change. 

Chemical    changes,    also    called    reactions,  when 


CHEMISTRY   DEFINED.  7 

expressed  by  means  of  symbols  and  signs  are  called 
equations. 

Chemistry  is  divided  into  (i)  Inorganic  and  (2) 
Organic. 

INORGANIC  CHEMISTRY  treats  of  the  metals 
and  nonmetals,  or  materials  coming  from  unorgan- 
ized (mineral)  sources. 

ORGANIC  CHEMISTRY  is  the  study  of  carbon 
and  its  compounds.  The  older  definition  of  organic 
chemistry,  and  the  reason  for  its  adoption  as  a  sepa- 
rate classification,  was  due  to  the  suppos'tion  that  the 
class  of  compounds  called  "organic"  originated  in 
living  tissue,  hence  of  plant  or  animal  origin.  We 
know  now  that  many  such  compounds  can  be  made 
artificially  from  carbon  and  the  inorganic  elements. 
The  term  "organic  chemistry,"  however,  survived. 


CHAJ>TKR  II. 
GENERAL  DISCUSSION. 

In  order  to  conveniently  study  the  elements  which 
are  of  importance  to  the  student  chemist,  it  is  nec- 
essary to  classify  them.  Many  systems  of  classifi- 
cation have  been  proposed,  many  purely  arbitrary, 
but  all  open  to  criticism.  Berzelius  was  the  first  to 
divide  the  elements  into  two  large  classes  which  he 
called  "metals"  and  "metalloids." 

The  metals  he  considered  to  be  those  which  possess 
luster  and  opacity,  easily  conduct  heat  and  electricilv, 
and  are  electro-positive  in  their  combinations. 

The  metalloids — also  called  nonmelals — consist  of 
gases,  or  if  solids,  possess  no  luster,  ductility  or  mal- 
leability, are  poor  conductors  of  heat  ^nd  electricity 
and  are  electro-negative  in  their  combinations. 

We  know  that  this  classification  serves  only  in  a 
general  way,  for  a  number  of  the  elements  are  posi- 
tive in  one  combination  and  negative  in  another; 
some  metalloids  possess  a  luster;  some  form  alloys 
with  metals;  some  form  both  acids  and  bases  and, 
owing  to  these  properties,  may  {)roperly  be  placed  in 
both  divisions. 

The  most  reasonable  method  of  classification  is  by 

dividing  the  elements  into  groups,  which  is  the  system 

first  i)roposed  by  Ncwlands,  but  later  developed  bv 

MendelejefT.     This  is  the  method  most  commonl\ 

8 


coMPOUNns.  9 

used.  It  is  based  upon  the  atomic  weights  and  is 
known  as  the  ''Periodic  Lwic."  The  system  will  \)C 
fully  described  in  Chapter  XVI. 

This  classification,  also,  has  irregularities,  but  it 
seems  to  be  the  best  at  hand  and  has  stood  the  test 
of  years.  Our  method  of  grouping  is  very  arbitrary. 
We,  of  course,  retain  the  two  divisions  of — metals 
and  nonmetals — but  take  up  the  study  of  non- 
metals  first,  since  it  is  by  far  the  smaller  group. 
The  metals,  however,  we  have  grouped  according  to 
their  behavior  with  reagents,  which  is  considered' 
most  advantageous  for  the  i)ractica]  work  of  the 
pharmaceutic  chemist. 

COMPOUNDS  AND  MECHANICAL  MIXTURES.— 
These  are  dift'erentiated  as  follows: 

In  a  mechanical  mixture  there  is  no  true  union  of 
the  elements;  in  a  compound  there  is.  A  mixture 
possesses  all  the  properties  of  its  ingredients,  and 
these  ingredients  can  be  mixed  in  any  arbitrary 
proportions.  A  chemical  compound,  on  the  other 
hand,  possesses  entirely  different  properties  than  the 
elements  composing  it,  and  its  components  are  defi- 
nite, fixed  and  invariable.  Example:  if  iron  is  re- 
duced in  a  mortar  to  the  finest  possible  powder,  and 
if  ordinary  sulfur,  also  in  fine  powder,  is  mixed  with 
it  intimately,  the  mixture  will  present  a  uniform 
appearance.  If,  however,  a  small  quantity  of  it 
is  placed  under  a  microscope  the  particles  of  iron 
and  sulfur  will  be  found  lying  side  by  side.  If 
we  now  use  a  magnet  we  can  pick  out  the  iron  filings 
and   leave   the   sulfur  behind,  or  we  can  treat  the 


lO  PHARMACEUTIC    CHEMISTRY. 

mixture  with  carbon  disulfid  which  dissolves  the 
sulfur  and  leave  the  iron  behind.  But,  if  a  portion 
of  the  mixture  is  heated  to  redness,  a  chemical  change 
occurs  and  a  true  compound  is  formed,  in  which 
neither  the  sulfur  nor  the  iron  can  be  revealed  under 
the  most  powerful  microscope.  The  product  pos- 
sesses properties  unlike  either  of  its  composing  ele- 
ments and  a  magnet  is  now  incapable  of  abstracting 
iron  from  it,  and  carbon  disulfid  will  not  dissolve 
out  the  sulfur.  This  is,  therefore,  an  illustration 
of  the  fact  that  before  heating  it  was  simply  a  me- 
chanical mixture,  while  after  heating  we  had  a  true 
chemical  compound  (ferrous  sulfid,  FeS).  Another 
proof  that  this  is  a  chemical  compound  is  that  when 
it  is  treated  with  dilute  sulfuric  acid  a  gas  possessing 
the  odor  of  bad  eggs  is  evolved.  Neither  the  iron 
nor -sulfur  treated  with  sulfuric  acid  before  they  are 
combined  will  evolve  this  gas. 

ELEMENTS  AND  COMPOUNDS.— As  was  said 
above,  elements  are  bodies  that  have  resisted  all 
attempts  to  decompose  them  into  simpler  forms  of 
matter.  Thus,  silver,  gold,  copper,  are  solid  ele- 
ments; bromin  and  mercury  are  liquid  elements; 
hydrogen,  oxygen,  nitrogen,  chlorin  and  fluorin  are 
gaseous  elements.  Elements,  therefore,  exist  in  all 
three  forms  of  aggregation. 

A  compound  was  defined  as  a  body  composed 
of  two  or  more  elements  and  is,  therefore,  capable 
of  being  split  up  into  its  components.  Thus,  mer- 
curic oxid,  HgO,  is  composed  of  mercury  and  oxy- 
gen, and  hv  siinpl\-  heating  il.  it  is  possible  to  resolve 


ATOMIC    WEIGHT.  11 

it  into  mercury  and  oxygen,  the  first  being  a  liquid 
metal,  the  latter  a  gas. 

The  elements  are  divided  into  two  series:  the 
nonmetals  and  the  metals.  There  are  sixteen  non- 
metallic  elements,  the  balance  are  all  metals.  All 
metals  are  capable  of  being  polished.  They  possess 
a  peculiar  surface  referred  to  as  "metallic  luster." 
They  are  all  white  to  light  blue  or  gray,  with  the  ex- 
ception of  gold  which  is  yellow  and  copper  which  is 
of  a  red  color.  The  nonmetals,  on  the  other  hand, 
are  destitute  of  the  metallic  luster,  and  such  elements 
as  phosphorus,  sulfur  and  carbon  are  examples  of 
the  nonmetals. 

SYMBOLS. — A  symbol  may  be  said  to  be  a  short- 
hand method  of  representing  an  element.  For  con- 
venience in  writing  chemical  reactions  and  for  many 
other  reasons  these  symbols  are  employed.  They 
are  usually  the  initial  letters  of  the  Latin  name  of  the 
elements.  Thus,  H  stands  for  hydrogen ;  O  for  oxy- 
gen; N  denotes  nitrogen;  S  sulfur;  P  phosphorus, 
etc.  When  more  than  one  element  have  names 
beginning  with  the  same  initial  letter,  another  charac- 
teristic letter  is  added.  The  first  letter  is  always  a 
capital,  the  second  usually  small.  Thus,  Hg  for 
hydrargyrum;  Os  for  osmium;  Ni  for  nickel;  Sb 
for  stibium;  Pb  for  plumbum. 

ATOMIC  AND  MOLECULAR  WEIGHTS.— The 
elements  possess  definite  weights  of  their  own.  The 
atomic  weights  of  the  elements  represent  (a)  the 
relative  weights  of  the  atoms  compared  with  hy- 
drogen; (b)  the  smallest  quantity  by  weight  which  can 


12  PTTARMACEL'TIC    CHEMTSTRY. 

enter  a  chemital  comijound,  this  also  compared  with 
hydrogen;  (c)  the  specific  gravity  of  the  element 
in  the  gaseous  state  as  compared  with  hydrogen. 
The  atomic  weight  of  any  element,  therefore,  is 
the  number  of  times  its  atom  is  heavier  than  an  atom 
of  hydrogen.  Hydrogen,  being  the  lightest  sub- 
stance known,  is  generally  used  as  the  standard  of 
weight  for  the  elements.  Its  atomic  weight  is  taken 
as  unity;  that  is,  it  weighs  one  microcrith.  When, 
therefore,  we  speak  of  oxygen  having  the  atomic 
weight  of  1 6,  we  understand  it  to  weigh  sixteen  times 
as  much  as  the  hydrogen  atom,  or  that  it  weighs  i6 
microcriths.  In  the  same  way  we  determine  that 
the  atomic  weight  of  carl)on  is  12;  nitrogen,  14; 
sodium,  23;  potassium,  39;  calcium,  40,  etc. 

Molecular  weight  of  a  compound  is  the  sum  total 
of  the  atomic  weights  in  a  molecule  of  the  substance. 
Thus,  CaO  represents  a  molecule  of  calcium  oxid, 
or  common  lime;  from  its  formula  we  see  it  is  com- 
posed of  one  atom  each  of  calcium  and  oxygen. 
Now,  the  atomic  weight  of  calcium  is  40  and  that 
of  oxygen  is  16.  If  we  now  add  40  and  16  we  obtain 
the  sum  total  of  the  atomic  weights  in  the  molecule, 
or  56;  56,  therefore,  is  the  molecular  weight  of  cal- 
cium oxid.  Common  chalk,  as  another  example, 
has  the  formula  CaCOj.  We  find  here  a  molecule 
composed  of  one  atom  of  calcium  which  weighs 
40;  one  atom  of  carbon,  atomic  weight  12;  and  three 
atoms  of  o.xygen,  atomic  weight  16 — taken  three 
times,  or  48.  If  we  now  add  (40  -f-  12  -f  48  =  100), 
the  atomic  weights  of  each  of  the  elements  in  the 


VALENCE.  13 

molecule,  we  obtain  the  sum  of  100,  which  is  the 
molecular  weight  of  calcium  carbonate,  or  chalk. 

QUANTIVALENCE,  ATOMICITY,  VALENCE  OR 
"BONDS." — By  the  valence  of  an  element  its  atom- 
fixing  power  is  meant.  It  may  be  defined  as  "  the 
combining  power  of  the  atoms  of  an  element  as  com- 
pared with  that  of  hydrogen."  It  will  be  seen  here 
that  hydrogen  is  a  unit  of  valence  as  well  as  a  unit  of 
weight.  Atoms  of  certain  elements  have  a  combin- 
ing power  equal  to  the  atoms  of  hydrogen.  Thus, 
one  atom  of  chlorin  unites  with  one  atom  of  hydro- 
gen. Hydrogen,  being  the  unit,  has  a  valence  of  i, 
and  is  called  a  monad  or  a  univalent  element.  It 
therefore  has  i  combining  or  replaceable  "bond." 
Oxygen  has  a  valence  of  2,  it  is  spoken  of  as  a  dyad 
and  has  2  combining  or  replaceable  bonds.  Nitro- 
gen is  a  triad,  having  3  replaceable  bonds;  carbon,  a 
tetrad,  having  4  bonds,  and  phosphorus,  a  pentad, 
having  5  bonds.  It  will  be  seen  that  to  neutralize 
the  two  bonds  of  oxygen  two  hydrogen  atoms  will 
be  required,  thus:  — O —  shows  the  two  bonds  of 
ox3'gen,  and  H — O — H  shows  these  two  bonds 
united  to  two  monad  hydrogen  atoms,  forming  a 
"saturated"  or  "perfectly  balanced"  compound. 
Nitrogen,  having  three  bonds,  must  be  united  with 
3    hydrogen    atoms   in   order  to   form    a   saturated 

/H 

compound.     Thus,       N- -H    shows     the    nitrogen 
\,H 

atom    to    be  saturated,  giving  rise  to  a  compound 
having  the  fcjrmula  NH3,  and  commonly  called  am- 


14  PHARMACEUTIC    CHEMISTRY. 

monia  gas,  etc.  Thus,  it  will  be  seen  that  elements 
can  be  divided  according  to  their  bonds  or  combining 
values  into  monads,  dyads,  triads,  tetrads,  pentads, 
hexads  and  heptads  accordingly  as  they  can  replace 
I,  2,  3,  4,  5,  6  or  7  hydrogen  atoms  or  its  equivalent 
in  the  molecule. 

VARIABLE  VALENCE.— While  an  element  has 
always  the  same  valence  in  the  same  compound,  it 
may  exhibit  a  different  valence  in  different  com- 
pounds. Thus,  nitrogen,  as  has  been  seen  in  the  case 
of  ammonia,  exhibited  the  valence  of  3.  In  nitric  acid, 
however,  and  in  all  the  nitrates  it  is  always  5.  Many 
other  elements  have  this  variable  valence.     Thus: 

Sulfur,  Chromium,  Manganese  act  as  dyads,  tetrads 
and  hexads. 

Arsenic,  Antimony,  Phosphorus  act  as  triads  and 
pentads. 

Carbon  acts  as  dyad  and  tetrad. 

Iron  acts  as  dyad  and  triad. 

Tin  acts  as  dyad  and  tetrad. 

CHEMICAL  FORMULAS.— A  formula  is  an  ex- 
pression of  the  composition  of  a  molecule.  It  con- 
sists usually  of  two  or  more  symbols  written  together, 
and  represents  a  definite  molecular  weight.  If  water, 
represented  by  the  formula  HjO,  is  taken  for  example, 
it  is  seen  to  be  composed  of  two  parts  by  weight 
of  hydrogen  and  16  jiarts  by  weight  of  oxygen;  the 
molecular  weight  of  water,  therefore,  is  18.  KCl 
is  the  formula  for  potassium  chlorid  and  rejiresents 
74.4  jxirts  of  ])otassium  chlorid,  which  is  the  sum 
total  of  39,  the  atomic  weight  of  potassium, and  ,:;5.4. 


COMPOUNDS    CLASSIFIED.  I  5 

the  atomic  weight  of  chlorin.  When  we  desire  tt) 
represent  more  than  one  atom  of  an  element  it  is  nec- 
essary to  affix  a  small  numeral  at  the  lower  right-hand 
corner  of  the  symbol  representing  the  element.  Thus 
Na2  represents  two  atoms  of  sodium,  or  46  parts  of 
sodium  by  weight.  In  the  same  way  O3  represents 
3  times  the  atomic  weight  (16),  or  48  parts  of  oxygen 
by  weight. 

Common  soda  has  the  formula  Na2C03;  if  we 
wish  to  represent  more  than  i  molecule  of  common 
soda,  we  place  a  large  numeral  before  the  formula. 
Thus,  3Na2C03  represents  3  molecules  of  soda,  the 
3  multiplying  each  of  the  atoms  in  the  molecule. 
4HCI  represents  4  molecules  of  hydrochloric  acid  and 
stands  for  4  hydrogen  and  4  chlorin  atoms.  2H2SO4, 
on  the  other  hand,  is  the  formula  of  two  molecules  of 
sulfuric  acid  and  it  stands  for  4  atoms  of  hydrogen, 
2  atoms  of  sulfur  and  8  of  oxygen.  Thus  the  nu- 
meral placed  before  the  molecule  multiplies  all  the 
atoms  in  the  molecule,  while  a  numeral  placed  after 
a  symbol  multiplies  only  that  one  symbol. 

If  a  group  of  symbols  (NH^)  is  followed  by  a  nu- 
meral, the  whole  group  is  multiplied  by  that  numeral. 
Thus,  (NHJ3  stands  for  3  molecules  of  ammonium; 
(NO)^  stands  for  4  molecules  of  nitric  oxid,  etc. 

CLASSIFICATION  OF  COMPOUND^.-- Com- 
pounds are  classified  into  leases,  acids  and  salts. 

Bases  are  the  hydroxids  of  the  metals.  Some 
bases  are  soluble,  others  not.  The  soluble  bases 
have  a  caustic  taste  and  turn  red  litmus  paper  ])luc. 
Slaked  lime  is  a  common  example  of  the  bases. 


l6  PHAKMACKUTIC    (  HEMISTRY. 

Acids  are  defined  as  the  salts  of  hydrogen.  They 
have  a  sour  taste,  are  corrosive  and  turn  blue  litmus 
red. 

Salts  are  acids  in  which  part  or  all  the  basic  hydro- 
gen has  been  replaced  by  a  metal.  Salts  are  named 
after  the  element  and  the  acid  from  which  formed. 
Thus,  if  potassium  replaces  the  hydrogen  of  sulfuric 
acid — potassium  sulfate  is  formed. 

The  salts  are  usually  classified  or  subdivided  into 
normal,  acfd,  basic  and  double  salts. 

A  normal  salt  is  an  acid  in  which  all  the  basic  or 
replaceable  hydrogen  has  been  replaced  by  a  metal, 
as  in  potassium  tartrate  (KsC^H^Og). 

An  acid  salt  is  one  in  which  not  all  of  the  basic 
hydrogen  of  the  acid  has  been  replaced,  as  in  ])otas- 
sium  bitartrate  (KHC^H^OJ. 

A  basic  salt  is  an  acid  in  which  part  of  the  hydrogen 
has  been  replaced  by  a  metal  and  another  part  by  an 
oxid  or  a  hydroxid.  Thus,  basic  lead  acetate  (lead 
sjI  acetate)  serves  a  good  example:  Pb(PbO) 
(C,H30,).,. 

Adouble  salt  is  an  acid  in  which  the  basic  hydrogen 
is  replaced  by  two  metals.  Example:  Potassium, 
sodium  tartrate  (Rochelle  salt)— KNaC^H^Og. 

CLASSES  OF  ACIDS.— The  acids  are  divided  into 
those  con'taiiiing  no  t)xygen^  which  are  termed  liy- 
dracids,  and  those  containing  t)xygen  which  are 
termed  oxacids.  Tlie  names  of  all  hydnuids  i)egin 
with  llie  jjrefix  hydro  and  the  names  of  their  ."^alts  end 
witli  the  suflix  id  (ide).  K.xamples:  .Acid  hydro- 
chloric,   acid     hvdriodic,    acid    hvdrobromic.    acid 


nonmf:tals  classified.  17 

hydrosulfuric.  Such  well-known  acids  as  sulfuric, 
nitric  and  oxalic  belong  to  the  class  of  oxacids. 
In  the  oxacids  the  quantity  of  oxygen  present  in 
the  acid  determines  their  names.  Thus,  names 
of  acids  containing  lea.t  oxygen  begin  with  hypo 
and  end  in  ous.  Those  containing  the  next  larger 
quantity  of  oxygen  end  in  ous  omitting  the  hypo. 
The  next  higher  acid  ends  in  ic,  while  the  high- 
est acid  begins  with  per  and  ends  in  ic.  The  fol- 
lowing chlorin  oxacids  serve  as  examples:  Hy- 
pochlorous  acid  (HCIO),  chlorous  acid  (HClOj), 
chloric  acid  (HCOj),  perchloric  acid  (HCIO,). 

CLASSIFICATION  OF  THE  NONMETALS. 

The  nonmetals,  grouped  according  to  their  valences, 
are  as  follows: 


Hydrogen  Group: 

Hyflrogcn H 

Chlorin  Group : 

Chlorin CI 

Bromin Br 

lodin I 

Fluorin  . F 

Sulfur  Group : 

Oxygen O 

Sulfur ]  S 

Selenium |  Se 

Tellurium Te 

Nitrogen  Group : 

Nitrogen '  N 

Boron B 

Phosphorus I  P 

Carbon  Group : 

Carbon (" 

Silicon Si 


CHAPTER  III. 

THE   NONMETALS. 

HYDROGEN. 

A  GASEOUS  element.  Symbol,  H.  Atomic  weight, 
I.  Molecular  weight,  2.  Valence,  i.  Density,  i. 
Weight  of  one  liter  =  0.0899  gm.  (0.09).  One  gram 
of  hydrogen  at  0°  C.  and  760  millimeters  pressure 
will  occupy  1 1. 1 6  liters  of  space. 

Occurrence. — Hydrogen  was  discovered  by  Caven- 
dish (1766).  It  occurs  in  the  free  state  in  gases  from 
volcanoes,  several  semi-active  fumaroles  and  in  the 
atmosphere  of  the  sun.  In  combination  it  is  a  con- 
stituent of  water  and  in  most  organic  substances  of 
both  animal  or  vegetable  origin.  It  is  a  necessary 
constituent  of  all  acids,  bases  and  ammoniacal  com- 
pounds. Does  not  exist  free  on  the  earth,  but  has 
been  found  free  in  meteorites  which  have  fallen 
upon  the  earth. 

Preparation. — Hydrogen  is  produced  by  the  fol- 
lowing methods: 

(i)  Electrolytic  decomposition  of  water;  hydrogen 
collecting  upon  the  negative  pole. 

H.,0  -f  electrolysis  =  H,  +  O. 

(2)  By  the  action  of  metallic  sodium  or  potassium 
on  water. 

2H,0  +  Na,  =  2NaOH  +  H^. 
18 


HYDROGEN.  Jg 

(3)  Action  of  steam  on  red-hot  iron. 

4H2O  +  3Fe  =  FegO^  +  H^. 

(4)  Chemical  reactions.  Decomposition  of  mineral 
acids  by  a  metal,  usually  zinc  or  iron,  and  dilute 
sulfuric  acid. 

H2SO,  +  Zn  =  ZnSO,  +  H,. 

This  latter  method  is  usually  employed  in  labora- 
tories. Dilute  sulfuric  acid  is  used  to  prevent  the 
crystallization  of  the  zinc  sulfate  produced.  If  ab- 
solutely pure  zinc  is  used,  no  action  will  take  place 
unless  an  electric  current  is  passed  through  the  solu- 
tion. Since  commercial  zinc  is  usually  employed, 
the  hydrogen  obtained  is  not  entirely  pure,  but  con- 
tains some  other  gases  derived  from  the  impurities 
of  the  zinc. 

Properties. — When  pure  and  at  normal  temperature 
and  pressure,  hydrogen  is  a  colorless,  transparent, 
odorless  and  tasteless  gas.  It  is  invisible,  combus- 
tible, but  does  not  support  combustion.  Burns 
with  a  pale-blue  flame,  forming  water.  Hydrogen 
produces  more  heat  than  any  other  known  substance, 
weight  for  weight.  It  is  14.5  times  lighter  than  air, 
and  is  the  lightest  substance  so  far  known.  It  is 
almost  insoluble  in  alcohol,  and  at  a  temperature  of 
— 240°  C  and  a  pressure  of  650  atmospheres,  it  has 
been  liquefied  to  a  steel-blue  liquid.  It  has  not  been 
permanently  lic^uefied,  however,  and  is  practically 
the  only  gas  that  has  not  been  so  condensed.  Its 
boiling-point  is  stated  as  — 243°  C,  and  its  critical 
temperature,  — 233°  C.  It  is  the  best  conductor  of 
heat  and  electricity  among  the  gase'^ 


20  PHARMACEUTIC    CHEMISTRY. 

It  is  very  diffusible,  passing  through  most  glasses 
slowly,  but  is  chemically  inactive  under  ordinary 
conditions.  It  is  nonpoisonous,  but  will  not  support 
respiration  of  animals. 

It  will  readily  unite  acids  with  other  elements  at 
the  moment  of  its  formation  (nascent  state). 

Its  use  in  nature  is  to  assist  in  formation  of  water 
and  of  vegetable  and  animal  tissues. 

In  the  arts  hydrogen  is  used  for  heating  and 
illuminating  purposes,  as  a  lifting  power  in  balloons, 
etc.,  but  its  uses  are  quite  limited.  The  oxyhydro- 
gen  blcnvpipe  offers  a  means  of  employing  its  great 
heat  value  (3000°  C). 

In  the  laboratory  it  is  the  ideal  reducing  agent, 
and  is  widely  used  as  such. 

Compounds. — With  oxygen  it  forms  hydrogen 
monoxid— water,  HjO.  (For  description  of  waters, 
see  Chapter  VI.)  It  also  forms  hydrogen  peroxid, 
H2O2,  a  colorless,  odorless  liquid  with  an  astringent 
taste  which  acts  as  an  oxidizing  agent,  but  may  also 
act  as  a  reducing  agent.  Hydrogen  dioxid  (peroxid) 
decomposes  readily,  even  spontaneously,  and  is  now 
best  preserved  by  adding  0.2  %  of  acetanilid.  Used 
as  a .  bleaching  agent,  disinfectant  and  antiseptic. 
Also  as  a  cleansing  and  oxidizing  agent. 

OXYGEN. 

History. — O.xygen  was  iiuk'pcndcn(I\  discovered 
])y  Priestley  in  England  in  1774  and  by  Scheele  in 
Sweden  at  the  same  time,  thougli  Scheele's  results 
were  not  ]>ublished  until  1775. 


Priestley  was  heating  some  red  mercuric  oxid 
under  a  reading-glass  by  concentrating  the  sun's 
ravs  upon  it,  when  it  changed  to  metallic  mercury 
and  liberated  a  gas.  He  called  this  gas  "  dephlogisti- 
cated  air,"  Scheele  obtain. d  his  oxygen  by  heating 
"braunstein  "  (dioxid  of  manganese),  and  called  it 
"empyreal  air"  on  account  of  its  power  of  support- 
ing combustion. 

A  few  years  later,  Lavoisier  proved  both  gases  to 
be  identical  and  applied  the  present  name  oxygen 
(the  name  meaning — produc'ng  sour),  from  the 
erroneous  idea  he  had,  that  oxygen  was  necessary  to 
acid  production. 

Occurrence. — Oxygen  is  present  in  the  air  mixed 
with  about  four  times  its  volume  of  nitrogen  and 
other  gases. 

Combined,  it  is  the  most  abundant  element,  com- 
posing f  of  water  and  almost  §  of  rocks  composing 
the  earth's  crust,  also  in  vegetable  and  animal  tissues. 

It  is  present  in  nearly  all  natural  substances  and 
almost  everywhere. 

Preparation. — (i)  By  heating  red  mercuric  oxid. 
2HgO  +  heat  =  2Hg  +  ©3. 

(2)  By  heating  black  oxid  of  manganese. 

3Mn02  +  heat  =  MngO^  -|-  Oj. 

(3)  By  heating  potassium  chlorate. 

2KCIO3  +  heat  =  2KCI  +  3O2. 

If    manganese    dioxid    and    potassium    chlorate 

are  mixed  and  heated,  the  oxygen  is  given  off  at  a 

much   lower   temperature,    the   potassium   chlorate 

giving    up    the    oxygen,  the  manganese  dioxid  re- 


22  PHARMACEUTIC    CHEMISTRY. 

maining  unchanged,  merely  acting  as  a  catalyzing 
agent.  Catalytics  enhance  chemical  reaction  with- 
out themselves  becoming  involved  in  it. 

(4)  2KCIO3  +  2Mn02  =  2KMnO,  +  CI,  +  O^. 

(5)  2KMnO,  =  KjMnO,  +  MnO^  +  O^." 

(6)  K^MnO,  +  CI,  =  2KCI  +  MnOs  +  O,. 

Physical  Properties. — Oxygen  is  a  colorless,  taste- 
less and  odorless  gas.  It  is  slightly  heavier  than 
air  and  16  times  as  heavy  as  hydrogen.  One  liter 
of  the  gas  under  standard  conditions  weighs  1.43028 
gms.  It  is  slightly  soluble  in  water,  thus  affording  the 
oxygen  for  the  respiration  of  water  animals  and 
plants.  Oxygen  can  be  liquefied  under  reduced 
temperatures  and  increased  pressure. 

It  does  not  burn,  but  supports  combustion.  Unites 
with  all  elements  but  fluorin,  forming  oxids  of 
three  classes.  Acid  oxids  are  those  which,  when 
added  to  water,  produce  acids.  Basic  oxids  are 
those  which,  when  water  is  added,  produce  bases. 
Neutral  oxids  do  not  form  either  bases  or  acids 
with  water.     Examples: 

(i)  PP,  +  3H2O  =  2H3PO, 

(2)  BaO  +  H2O  =  Ba(OH),. 

(3)  MnOj  +  H20=  iio  change. 

Oxygen  possesses  very  powerful  ])roperties  chemi- 
cally. Most  of  the  natural  atmospheric  changes  are 
due  to  oxygen. 

Its  chief  function  is  to  support  combustion.  The 
greatest  type  of  combustion  is  that  of  respiration — 
in  which  we  take  air  into  the  lungs,  separate  the 
oxygen  and  eliminate  it  from  the  body  in  the  form  of 


OZONE.  2^ 

carbon  dioxid,  CO^.  It  assists  in  the  Inirning  up  of 
waste  tissues  in  the  blood. 

Chemically,  oxygen  is  the  typical  oxygenizing 
agent.  It  is  used  in  the  oxyhydrogen  blowpipe  to 
produce  intense  heat,  and  with  lime,  intense  light. 

Oxygen  plays  its  part  medicinally  as  a  stimulant 
and  tonic.     Ozone  is  an  allotropic  form  of  oxygen. 

Ozone  was  discovered  in  1785  by  Von  Marum  and 
called  electrified  oxygen.  Schonbren  in  1840  deter- 
mined its  composition. 

When  air  or  oxygen  is  exposed  to  the  action  of  elec- 
tric sparks,  it  undergoes  a  peculiar  change,  acquiring 
a  strong,  pungent  odor,  contracting  in  volume  and  ex- 
hibiting other  new  properties.  Ozone  may  also  be 
obtained  by  several  other  means.  It  has  a  density 
of  24,  a  molecular  weight  of  48,  and  is  represented 
by  the  graphic  formula: 

o\ 

I     o  =  o, 

0/ 

It  is  present  in  the  atmosphere  one  part  in 
700,000. 

The  peculiar  power  that  certain  elements  thus 
have  of  assuming  more  than  one  form  is  known  as 
allotropy. 

The  properties  of  ozone  are  those  of  oxygen, 
but  intensified. 

Preparation. — (i)   By  subjecting  oxygen  to  low 
temperature  and  high  pressure: 
3Q2    ^203 
oxygen     ozone 


24  PHARMACEUTIC    CHEMISTRY. 

(2)  In  dilute  form,  by  acting  with  .stron,!:f  sulfuric 
acid  on  barium  dioxid: 

sBaO,  O, 

r       -/.     ..  +  3H,SO,  =3BaSO,  +  3H,0  + — 

barium  dioxid      "^    '       '     "^  4  1  .)    2         ozone. 

The  compound  of  o.xvgen  and  hydrogen  constitute.s 

water.  H^O,  which  will  be  discussed  in  Chapter  VI. 

NITROGEN. 

A  gaseous  element.  Symbol,  N.  Atomic  weight,  14. 
Valence,  3  or  5.  Density,  14.  One  liter  weighs  1.256 
grams. 

Occurrence. — Nitrogen  exists  free  in  the  air  mixed 
with  oxygen,  argon,  etc. ;  also  free  in  the  gases  of  the 
stomach,  intestines,  blood,  urine,  etc.  Combined,  it 
occurs  as  nitrates  of  potassium,  sodium  and  calcium 
in  animal  and  vegetable  tissue  and  in  ammonia  com- 
pounds. 

History. — It  was  discovered  in  1 772  by  Rutherford, 
who  called  it  "mephitic  air"  (meaning  poisonous 
to  life) .  Lavoisier  called  it  azote  for  the  same  reason. 
Scheele  first  recognized  it  as  a  constituent  of  air. 

The  jjresent  name,  nitrogen,  was  suggested  by 
Chaptal,on  account  of  its  being  a  constituent  of  niter, 
hence  a  "niter  producer." 

Properties. — Nitrogen  is  a  colorless,  odorless,  taste- 
less, invisible  gas;neither  combustible  nor  a  supporter 
of  combustit)n;  nonpoisonous,  will  not  support  life. 
Soluble  in  water,  lighter  than  air;  chemically  very 
inert. 

l'r€ptiratioH.  —  {\)  By  burning  phospliorus  in  air. 
2P,  4-  Air  5(4  N,  +  O2)  =  2IV).,  +  20N 


NITROGEN.  25 

The   P2O5  (phosphoric  anhydrid)  is  then  absorbed 
by  water,  the  impure  nitrogen  remaining. 

(2)  By  heating  ammonium  nitri:e  to  decomposition. 
NH4NO2  +  heat  =  2H2O  +  Nj. 
The  nitrogen  so  obtained  being  pure. 

Function. — To  dilute  the  oxygen  of  the  air,  to  as- 
sist in  plant  growth  and  animal-tissue  formation  and 
is  of  great  value  in  many  ways  in  the  form  of  its  com- 
pounds of  nitrogen. 

With  hydrogen  it  forms  Ammonia,  NH3. 

A  colorless,  pungent,  irrespirable  gas,  freely  solu- 
ble in  water,  lighter  than  air,  liquetied  easily,  it 
emulsifies,  but  does  not  saponify  fats. 

Ammonia  is  found  usually  in  very  small  quantities, 
but  universally  distributed  in  the  atmosphere,  rain 
water,  soil,  sewer  gases,  urine,  etc.  It  is  produced 
naturally  by  dissociation  of  organic  compounds  of 
nitrogen  by  the  action  of  bacteria.  Its  chief  com- 
mercial source  is  the  "ammoniacal  liquor"  from 
gas-works. 

With  oxygen  it  forms  five  oxids: 

(i)  Nitrous  oxid,  N2O.     Laughing  gas. 

(2)  Nitric  oxid,  N2O2. 

(3)  Nitrogen  trioxid,  N2O3.     Nitrous  anhydrid. 

(4)  Nitrogen  tetroxid,  N2O4. 

(5)  Nitrogen  pentoxid,  N2O5.     Nitric  anhydrid. 
The  important  oxids  are  NjO,  NjO,  and  N2O5— 

these  forming  the  following  oxacids: 

(i)  N2O  +  H2O  =  2HNO.     Hyponitrous  acid. 

(2)  N2O3  +  H2O  =  2HNO2.     Nitrous   acid. 

(3)  N2O5  +  H2O  =  2HNO3.     Nitric  acid. 


26  PHARMACEUTIC    CHEMISTRY. 

The  most  im])ortant  of  these  latter  compounds  is 
nitric  acid  and  from  it  the  others  are  obtainable.  It 
will  be  fully  described  under  Acids,  Chapter  VIII. 

Nitrogen  monoxid,  N^O,  discovered  by  Priestley 
in  1793.  A  colorless,  odorless,  nearly  tasteless  gas. 
Incombustible,  but  supporting  combustion,  respirable 
to  a  limited  extent.  Obtained  by  heating  ammonium 
nitrate: 

NH,N03  +  heat  =  2H2O  +  N^O. 
Used  as  an  anesthetic  in  dentistry  and  minor  surgery 
since  1845. 

Nitrogen  trioxid,  NjOg,  unites  with  water  to 
form  nitrous  acid  and  hence  produces  nitrites  in 
natural  combination.  It  has  been  proven  not  to  exist 
in  a  gaseous  condition,  but  to  consist  of  a  mixture 
of  nitrogen  oxids. 

Nitric  anhydrid  or  nitrogen  pentoxid,  NjOj  is 
a  white,  solid  substance  at  low  temperatures  and 
decomposes  at  45  °,  evolving  brown  fumes  of  N2O3. 

When  added  to  water,  it  produces  nitric  acid, 
HNO3,  called  aqua  jortis  (strong  water). 

CARBON. 

A  solid,  multiform  element.  Symbol,  C.  Atomic 
weight,  12.     Valence,  4. 

Occurrence. — Found  both  free  and  in  comljination. 
All  carbon  except  the  incomjjustible  owes  its  origin 
to  animal  or  vegetable  life. 

Free,  it  is  found  in  three  distinct  forms:  (1) 
diamond,  (2)  graphite,  (3)  amorphous  carbon.  All 
varieties  are  insoluble  and  infusible,  l)ut  readily  com- 


CARBON.  27 

bustible,  having  a  strong  affinity  at  high  temperatures 
for  oxygen,  and  burning  to  form  COj.  All  but  the 
diamond  are  good  conductors  of  electricity. 

(i)  Diamond. — This  is  pure  carbon  when  colorless; 
but  with  certain  small  quantities  of  impurities  present, 
the  color  may  be  found  to  be  yellow,  blue  or  even 
black.  It  is  found  in  but  few  places,  the  most  im- 
portant being  the  South  African  diamond  fields 
of  Kimberley,  where  it  occurs  in  a  blue  cement  rock 
filling  the  craters  of  extinct  volcanoes.  It  is  also 
found  in  some  meteorites  and  very  small  crystals 
have  been  obtained  artificially. 

It  is  probably  due  to  vegetable  origin,  the  change 
taking  place  at  intense  temperature  and  great  press- 
ure during  great  length  of  time.  It  is  the  hardest 
of  all  substances  known,  hence  finds  much  use  as  a 
cutting  and  grinding  material.  The  brilliancy 
as  a  gem  is  due  to  its  high  refractive  power.  The 
diamond  itself  is  cut  or  polished  by  the  use  of  dia- 
mond powder. 

(2)  Graphite,  also  called  plumbago  and  black  lead, 
is  pure  carbon  of  vegetable  origin  crystalliz-'ng  in 
six-sided  plates.  Found  in  largest  quantities  in  Cey- 
lon and  New  York  State.  Is  black  in  color,  lustrous, 
and  is  used  for  lead-pencils,  lubricants,  cruciWes, 
stove  polishes  and  for  electrotyping,  is  infusible 
and  not  easily  burned.  In  crucibles,  pencils,  etc.,  it 
is  mixed  with  varying  proportions  of  clay.  It  is 
made  artificially  by  heating  coal  mixed  with  powdered 
iron  ore  to  a  very  high  temperature  by  means  of  the 
electric  current. 


28  PHARMACEUTIC    CHEMISTRY. 

The  amorphous  forms  are  obtained  artitkially  in 
the  form  of  coke,  charcoal,  l)oth  animal  and  wood, 
and  lami)hlack  or  oil  charcoal. 

The  amorphous  jonns  of  carbon:  Naturally, 
we  find  these  forms  of  coal  all  of  vegetable  origin 
resulting  from  the  effect  of  enormous  pressure  and 
heat,  accomjmnicd  by  a  peculiar  fermentation,  by 
means  of  which  the  oxygen  and  other  elements 
have  been  nearly  driven  off,  leaving  nearly  pure 
carbon. 

In  anthracite  the  process  has  progressed  much 
farther  than  in  bituminous  coal,  and  is  nearly  pure 
carbon  with  small  quantities  of  hydrogen  and  o.xygen. 
Bituminous  coal  contains  considerable  hydrocarbon 
compounds. 

Cannel  coal  is  a  resinous  variety. 

Lignite  is  still  more  recent  and  shows  even  the 
cellular  structure  of  the  wood  which  was  its  origin. 

Peat  is  partially  decomposed  moss. 

Petroleum  contains  compounds  of  carbon  and 
hydrogen.  It  is  quite  largely  distributed  throughout 
the  world.  It  varies  very  much  in  appearance  and 
properties,  but  is  usually  dark  in  color  and  very  odor- 
ous, often  due  to  sulfur  and  nitrogen  compounds. 

Artificially,  we  obtain  im])urc  carbon,  as  charcoal, 
of  several  forms: 

(i)  Charcoal. — Wood  charcoal,  obtained  by  burn- 
ing wood  with  insufficient  supply  of  o.xygen,  whereby 
the  most  readily  combustible  materials  are  burned, 
leaving  about  19%  of  nearly  pure  carbon.  Animal 
charcoal  is  similarly  made  by  combustion  of  bone  and 


CARBON.  29 

is  known  as  Ijone-black,  drop-bla'.k,  but  contains 
only  about  10%  of  carbon,  the  rest  being  bone-ash, 
or  calcium  phosphate,  used  in  sugar  refining. 

Coke  is  made  by  a  similar  combustion  or  distillation 
of  coal,  used  for  iron  making.  The  by-products  of 
coke  manufacturing  are  now  separated  and  find 
large  commercial  value. 

Lamp-black  is  prepared  by  insufficient  combustion 
of  petroleum,  gas  or  similar  organic  substances.  It 
is  used  as  a  black  pigment,  especially  in  printers' 
ink,  which  consists  of  lamp-black,  linseed  oil  and 
soap  as  its  chief  ingredients. 

In  combination,  carbon  is  also  present  in  carbo- 
nates, bicarbonates,  carbon  dioxid  gas  and  in  all 
organic  substances,  whether  of  animal  or  vegetable 
origin. 

Compounds  with  oxygen:  Carbon  monoxid  gas, 
CO,  not  native,  colorless,  slight  odor,  very  poison- 
ous. Nonsupporter  of  combustion,  combustible, 
slightly  soluble  in  water.  Prepared  from  oxalic 
acid: 
H2C2O,  -f  H2SO,  =  H2SO,  +  H2O  +  CO2  +  CO. 

Carbon  dioxid,  or  anhydrid,  CO,,  is  a  colorless, 
odorless  gas,  soluble  in  water,  nonsupporter  of  com- 
bustion and  incombustible.  Occurs  free  in  air  and 
many  waters,  and  is  formed  during  respiration,  com- 
bustion, decay  and  most  fermentations.  With  water 
it  is  supposed  to  form  carbonic  acid,  which  is  very 
unstable: 

H/:)  -K  CO,  =  H2CO3. 

The  carbonates  of  the  metals  are  very  important 


30  PHARMACEUTIC    CHEMISTRY. 

and  very  abundant.  Carbon  dioxid  is  usually  pre- 
pared from  marble: 

CaCOj  +  HjSO,  =  CaSO,  +  H.O  +  CO,. 
Preparations  of  C  with  nitrogen  we  have  the  cyano- 
gen compounds — very  poisonous:  CjN,,  cyanogen  is 
a  colorless  gas,  with  a  characteristic  odor,  combustible 
with  a  pink  flame;  HCN,  or  prussic  acid,  a  liquid, 
colorless,  volatile,  feeble  acid,  with  odor  of  bitter 
almonds,  prepared  by  acting  on  potassium  cyanid 
w'ith  dilute  sulfuric  acid: 

2KCN  +  H^SO,  +  HjO  =  K^SO,  +  H^O  +  2HCN. 
Acid  hydrocyanic  dilute,  U.  S.  P.,  contains  2%  ab- 
solute HCN.     Scheele's  prussic  acid  contains  4%. 


CHAPTER  IV. 
THE  HALOGEN   ELEMENTS. 

The  halogen  group  is  so  named  because  of  the 
close  resemblance  between  their  sodium  salts  and  sea 
salt,  the  term  halogen  signifying  "salt  producer." 
The  group  comprises  iodin,  chlorin,  bromin  and 
fluorin,  which  in  their  general  characteristics  strongly 
resemble  each  other  and  readily  change  places  in 
combinations  without  producing  any  very  marked 
change  in  the  character  of  the  compound. 

They  are  electronegative,  fluorin  being  most 
strongly  so  and  iodin  the  least  so.  They  have  a 
characteristic  pungent  odor  and  act  as  disinfectants 
and  bleaching  agents.  They  exhibit  a  regular 
physical  gradation  with  increase  in  atomic  weight. 
Thus  fluorin  and  chlorin  are  gases,  bromin  is  a  liquid 
and  iodin  is  a  solid  under  normal  conditions. 

Chemically,  they  show  the  same  graduation  of 
change;  with  hydrogen,  fluorin  unites  instantly  and 
so  eagerly  as  to  produce  explosion  by  mere  con- 
tact, even  in  the  dark.  Chlorin  will  not  unite  with 
hydrogen  except  in  the  light,  but  in  direct  sunlight 
does  so  rapidly,  producing  explosive  tendencies. 
Bromin  vapor  requires  a  flame  to  produce  union 
with  hydrogen,  and  iodin  vapor  and  hydrogen  re- 
quire to  be  strongly  heated  in  contact  with  spongy 
platinum. 

31 


32  IHfARMACKUTIC    CHEMISTRY. 

With  oxygen  they  unite  quite  difficultly  and  in 
inverse  order.  The  compounds  formed  are  rather 
unstable.     Bromin  and  fluorin  have  no  oxids. 

Fluorin  produces  no  oxacids  or  salts.  Thus,  the 
compounds  formed  are: 

Hydracids.  Oxids.  Oxacids. 

HF: 

HCl:     CKO  CUO,  CI2O5:  HCIO  HCIO,  HCIO,  HCIO4 
HBr:  HBrO  HBrOa  HBr04 

HI:  I2O,,  LO,:       HIO     HIO.     HIO3     HTO4 

FLUORIN. 

Fluorin  is  the  typical  group  clement:  \'alcncc,  1. 
Density,  19.    Atomic  weight,  19.    Specific  gravity,  1.3. 

History. — Very  recent  in  its  discovery,  for  it  was 
not  possible  to  isolate  it  until  1886,  when  Moissan 
finally  succeeded.  He  obtained  fluorin  by  passing 
an  electric  current  through  a  solution  of  jxjtas- 
sium  fluorid,  FK,  in  anhydrous  hydrofluoric  acid, 
HF.  Fluorin  he  separated  at  the  anode,  with  hydro- 
gen at  the  cathode,  the  reactions  taking  place  thus, 
the  breaking  up  of  the  acid  potassium  fluorid: 

2HFKF  =  F2  +  2HFK, 
The  reaction  is  carried  out  in  a  U-tube  of  platinum- 
iridium,  this  being  acted  ui)on  less  than  platinum 
alone. 

Occurreme. — Fluorin  occurs  in  combination  in 
considerable  quantities  as  native  Jhior-spar,  C^Y^, 
and  in  cryolite,  NagAIFo,  and  other  similar  com- 
pounds; also  in  small  amounts  in  bono,  tooth 
enamel  and  .'^ome  mineral  waters. 

Properties. — Of  all  known  eloments,  tUiorin  is  the 
most  active,   due   to   its   intense  chemiial  aftinities. 


FLUORIN.  33 

It  resisted  long  any  attempt  to  isolate  it,  for  if 
liberated,  it  instantly  recombined  with  the  materials 
of  the  vessel  in  which  the  separation  was  made. 

It  appears  to  be  a  colorless  gas,  with  a  character- 
istic irritating  odor;  but  even  this  is  of  doubtful  truth, 
for  with  the  moisture  of  the  air  or  of  the  mucous 
membranes  hydrofluoric  acid  is  instantly  produced, 
hence  the  true  odor  of  fluorin  is  not  certainly  known. 
All  metals,  even  gold  and  platinum,  are  acted  on  by 
fluorin  to  a  greater  or  less  extent  and  organic  com- 
pounds are  attacked  violently.  At  a  temperature 
of  — 185°,  it  condenses  to  a  liquid  condition.  This 
was  obtained  also  by  Moissan  and  Dewar  in  1897. 

The  liquid  is  a  yellowish,  mobile  fluid,  having  no 
action  on  silicon,  phosphorus,  sulfur  or  glass.  It 
attacks,  however,  hydrogen  and  hydrocarbons 
freely,  combining  violently  with  all  elements  except 
oxygen,  nitrogen  and  chlorin. 

Compounds. — Hydrogen  fluorid  or  hydrofluoric 
acid  is  prepared  by  the  action  of  strong  sulfuric  acid 
on  calcium  fluorid,  thus: 

CaF^  +  H^SO,  =  CaSO^  +  2HF. 
The  gaseous  acid  is  passed  into  water  in  leaden,  wax 
or    gutta-percha   bottles   as   it  attacks  glass.     The 
anhydrous  acid  is  prepared  by  heating  acid  potas- 
sium fluorid  in  platinum  retorts,  thus: 

HFKF  =  KF  -f  HF. 
It  is  a  colorless,  limpid,  fuming  liquid,  boiling  at 
19°  C.  It  is  used  as  a  solvent  of  glass  in  etching, 
etc.  It  is  exceedingly  dangerous  to  handle,  for  it 
produces  not  only  irritati(;n  to  m.ucous  surfaces,  but 
3 


34  PHARMACEUTIC    CHEMISTRY. 

severe  burns  upon  the  ilesh  and  often  serious  con 
stitutional  symptoms  and  death. 

CHLORIN. 

At.  \vt.,  35.5.  Valence,  1-3-5-7.  Sp.  gr.,  2.47. 
Density,  35.4.     Symbol,  CI. 

History. — Discovered  by  Scheele  in  1774  and 
thought  to  be  a  compound  of  oxygen  and  hydro- 
chloric acid.  He  called  it  "dephlogisticated  m.arine 
acid  gas,"  for  hydrochloric  acid  was  then  known  as 
"marine  acid."  In  1810,  Davy  gave  it  the  name 
chlorin,  on  account  of  its  greenish-yellow  color. 

Occurrence. — Always  in  combination  and  ver\- 
abundantly.  The  most  common  form  being  sodium 
chlorid. 

Preparation. — (i)  By  action  of  hydrochloric  acid 
on  manganese  dioxid. 

MnOj  +  4HCI  =  MnCl^  +  2H2O  +  2  CI. 

(2)  By  action  of  sulfuric  acid  on  manganese 
dioxid  and  sodium  chlorid. 

2NaCl  +  MnO,  -f-  2H,SO,  =  Na.SO,  -H  MnSO,+ 

2H20-t-2Cl. 

(3)  Slowly  generated  when  moistened  chlorinated 
lime  is  exposed  to  the  air. 

CO2  -f  CaO(Cl)2  =  CaCOg  -\-  CI,. 

Properties. — A  greenish-yellow  gas  2.5  times  as 
heavy  as  air,  pungent  and  suflfocating  odor.  Irre- 
spirable,  irritating,  soluble  in  water.  One  volume  of 
water  at  10°  C.  dissolves  3  volumes  of  gas.  Li(|Uor 
(  hlori  conipositus.  U.  S.  1'.,  is  a  0.4''^  solution. 

Li(|uid  chlorin  is  now  a  comnu-rcia!  arliile  and  is 


BROMIN.  35 

used  in  extractiun  of  gold  from  its  ores.    Sp.gr.  1.33; 
boils  at  33.6°  C. 

Chemically,  chlorin  is  very  active  and  especially 
noted  for  its  affinity  for  hydrogen  and  the  metals 
with  which  it  forms  chlorids.  Burns  in  an  atmos- 
phere of  hydrogen.  Its  allotropic  form  is  similar 
in  appearance,  but  is  inactive.  It  is  prepared  in  the 
dark.  The  well-known  bleaching  property  of  chlorin 
depends  upon  its  affinity  for  hydrogen,  it  decomposes 
the  moisture  liberating  oxygen  which  in  its  nascent 
state  energetically  decomposes  the  coloring  matters. 
Chlorin  will  net  bleach  a  perfectly  dry  substance. 
Compounds. — With  oxygen — none  important: 

CI2O,    chlorin  monoxid. 

CI2O3,  chlorin  trioxid. 

CI2O4,  chlorin  tetroxid. 
With   oxvgen  and  hydrogen  it  forms  the  acids  of 
chlorin: 

HCl,  hydrochloric  acid,  a  hydracid. 

HCIO,  hypochlorous  acid. 

HCIO2,  chlorous  acid. 

HCIO3,  chloric  acid. 

HCIO4,  perchloric  acid. 
The  important  acids  are  HCl,  HCIO,  HCIO3  and 
will  be  further  discussed  in  Chapter  VIII. 

BROMIN. 

Symbol,  Br.  At.  wt..  70.76.  Sp.  gr.,  2.99.  Va- 
lence, I. 

i/w/ory.— Discovered  by  Balard  (1826),  in  the 
sea-water  after  crystallizing  out  the  salt  from  con- 


oxacid^ 


36  PHARMACEUTIC    CHEMISTRY. 

centrated  solution.  He  gave  it  the  name  bromin 
(bromos,  signifying  a  stench),  on  account  of  its  dis- 
agreeable odor. 

Occurrence. — Never  free  in  nature.  Chiefly  com- 
bined with  the  alkaline  metals  and  magnesium  in 
sea-water  and  in  many  saline  and  salt  springs. 
The  saline  deposits  of  Stassfurt  contribute  a  large 
part  of  our  bromin  supply. 

Preparation. — Sea -water,  or  other  saline  brine, 
is  evaporated  and  several  crops  of  the  less  soluble 
materials  collected.  The  final  liquid  known  as 
"bittern,"  is  treated  with  chlorin  gas  which  liber- 
ates bromin,  thus: 

MgBr,  -h  CI,  =  MgCl,  +  Br,. 
This  is  then  shaken  out  with  ether,  removed,  treated 
with  potassium  hydroxid  and  evaporated  to  dryness, 
leaving  potassium  bromid  and  bromate. 

This  is  then  treated  with  manganese  dioxid  and 
sulfuric  acid,  liberating  pure  bromin. 

2KBr  +  MnO,  -f  2H,SO,  =  K,SO,  -F  MnSO,-|- 
2H2O  -^-  Br,. 

Properties. — A  heavy,  dark-red,  mobile  liquid, 
evolving  at  ordinary  temperature  a  reddish,  irrita- 
ting, pungent  odored  gas.  Soluble  in  thirty  parts 
of  water  and  readily  soluble  in  alcohol,  ether  and 
chloroform.  Chemical  properties  similar,  but  weaker 
than  those  of  chlorin.  Poisonous.  Recognized 
by  its  color  and  by  its  odor,  also  by  the  yellow  color 
of  its  solutions.  Is  separated  from  its  compounds 
by  chlorin,  and  may  I)e  so  identified.  Tmpurily 
iisua'l\-  present  is  l)romin  clilorid,  UrCi. 


lODIN.  37 

Compounds. — Similar  to  chlorin  compounds,  but 
less  stable. 

Hydrogen  bromid  or  hydrobromic  acid,  HBr,  is 
made  by  action  of  potassium  bromid  and  tartaric 
acid. 

KBr  +  H^C.H.Og  ==  HBr  +  KHC,H/)e. 

See  chapter  on  Acids,  page  71. 

lODIN. 

Symbol,  I.  At.  wt..  126.54.  Sp.  gr.,  4.95.  Val- 
ence, I. 

History. — In  1812,  Courtois  was  endeavoring  to 
prepare  niter  from  the  ashes  of  sea -weeds.  He  no- 
ticed the  beautiful  violet-colored  vapors.  It  remained 
for  Guy  Lussac,  however,  to  investigate  it  later  on. 
It  derives  its  names  from  the  color  of  its  vapor. 

Occurrence. — Similar  to  the  other  members  of 
this  group,  it  is  never  found  in  nature  asanuncom- 
bined  element.  It  is  associated  with  the  alkali 
metals,  with  magnesium  and  calcium.  Found  in 
niter  beds,  in  sea  and  mineral  spring  waters,  but 
most  largely  in  certain  sea-weeds  collected  off  the 
coast  of  Scotland  and  France,  and  from  the  ash  of 
these  weeds  our  commercial  supply  largely  comes. 
This  ash  is  obtained  at  as  low  a  temperature  as  pos- 
sible and  is  known  as  "kelp."  For  laboratory  uses 
iodin  can  be  obtained  in  the  same  manner  as 
chlorin,  thus: 

2KI  +  MnOj  +  2H2SO,  =  K^SO,  +  MnSO,+ 
2H2O  +  \,. 

Properties. — A    bluish -black,    shining    crystalline 


38  I'lIARMACKUTIC    CHEMISTRY. 

solid.  Crystallizes  in  scales  or  tablets,  emitting  an 
irritating  vapor.  Melts  at  114°  C.  It  is  poisonous, 
and  used  as  external  anodyne.  Its  salts  are  altera- 
tive when  used  internally. 

Free  iodin  turns  starch  paste  blue  and  may  be 
rendered  free  from  its  compounds  by  chlorin  gas. 
Acetate  of  lead  gives  a  yellow  precipitate  of  lead  iodid 
with  compounds  of  iodin; 

The  preparations  in  common  use  medicinally,  are: 
tincture  iodin,  a  7%  alcoholic  solution,  containing 
potassium  iodid; 

Liquor  iodi  compositus  {Lugol's  solution)  solution, 
of  iodin  and  potassium  iodid  in  water:  5  gms.  iodin, 
10  gms.  potassium  iodid,  in  100  gms.  of  the  solution; 

Hydr iodic  acid,  HI,  made  by  passing  hydrogen 
sulfid  gas  through  an  iodin  solution. 
I2  -f  H^S  =  2HI  +  S. 

Syrup  hydriodic  acid  contains  1%  HI.  Made 
by  reaction  of  potassium  iodid  and  tartaric  acid 
in  alcoholic  solution. 

KI  +  HAH^Oe  =  KHC.HPo  +  HI. 

The  chemical  compounds  are  similar  to  those  of 
bromin,  but  fewer  in  number  and  less  stable. 


CHAPTER  V. 

THE  SULFUR  GROUP. 

The  sulfur  group  consists  of  sulfur,  silicon,  phos- 
phorus, boron,  selenium  and  tellurium.  The  im- 
portant members  of  this  group  are  sulfur,  phos- 
phorus and  boron.  Silicon  is  worthy  of  some 
consideration,  while  selenium  and  tellurium  are 
of  little  importance  to  the  pharmaceutic  chemist. 
Sulfur,  as  the  most  important,  will  be  considered  first. 

SULFUR. 

Symbol,  S.  Sp.  gr.,  2.  At.  vvt.,  31.85.  Melts  at 
115°  c. 

History. — Sulfur  was  known  to  the  ancients. 

Occurrence. — Occurs  free  in  volcanic  areas,  and 
our  most  important  source  has  long  been  Sicily  and 
Italy.  Large  deposits  are  found  in  Iceland,  China, 
India,  California  and  the  Rocky  Mountain  districts. 
It  usually  occurs  mixed  with  clay,  from  which  it  may 
be  separated  by  distillation.  Beds  are  found  some- 
times in  which  the  sulfur  is  constantly  being  formed, 
due  to  chemical  changes,  and  such  beds  are  called 
"sulfatara." 

It  is  also  found  in  many  ores  in  combination  with 
metals,  as  sulfids  and  sulfates,  also  in  many  min- 
eral springs,  both  free  and  as  sulfids,  sulfates  or 
39 


40  I'flARMACEUTIC    CHEMISTRY. 

even  as  sulfuric  acid;  also  in  many  organic  ]>!anl 
and  animal  bodies. 

Properties. — Sulfur,  when  pure,  is  a  solid,  pale 
yellow,  dimorphous,  with  several  amorphous  modifi- 
cations. Melts  at  115°  C,  boils  at  448°  C.  Brittle, 
nearly  tasteless  and  odorless,  nonconductor  of  heat 
and  electricity.  Insoluble  in  water,  and  almost  so 
in  alcohol;  best  solvent  is  carbon  disulfid,  100  parts 
of  which  dissolves  37  parts  of  sulfur.  In  relation  to 
its  forms,  sulfur  may  be  divided  into  two  classes: 

A.  Those  soluble  in  carbon  disuliid. 

A.  (i)  Yellow,  opaque,  rhombic  octahedra. 

(2)  Long,  transparent,  needle-shaped  prisms;  these 
return  to  the  octahedra  after  a  few  days'  exposure. 

(3)  A  variety  of  lac  sulfur,  prepared  by  acting 
on  alkaline  polysulfids  with  a  mineral  acid. 

B.  Those  insoluble  in  carbon  disulfid. 

B.  (i)  A  tenacious,  amorjjhous  mass,  obtained  by 
pouring  sulfur  heated  to  230°  C.  into  cold  water. 

(2)  A  variety  of  lac  sulfur  prepared  by  acting 
on  a  thiosulfate  with  dilute  mineral  acid,  or  along 
with  flowers  of  sulfur  that  are  suddenly  cooled. 

Preparation. — Nearly  all  obtained  from  native 
sulfur  by  distillation.  A  small  amount  from  iron 
pyrites.  In  laboratory  practice  it  may  be  prepared 
by  several  means,  such  as  the  reaction  of  hydrogen 
sulfid  and  sulfur  dioxid: 

2H,S  +  S()2  =  2H2O  +  3S. 
Also   by    Imrning   h}drogen  sulfid  with  insuflaiont 
supply  of  air,  thus: 

2H2S  4-  O  =  HjO  +  S.,. 


SULFUR.  41 

Sulfur  is  also  a  by-product  in  smelting  of  copper 
pyrite  and  in  the  vat  waste  of  the  LeBlanc  process 
of  preparing  sodium  carbonate. 

Official  sulfurs  and  preparations:  Sublimed  sul- 
fur, flowers  of  sulfur,  obtained  by  vaporizing  and 
condensing  sulfur.  This  is  not  pure,  contains  possi- 
ble impurities  and  sulfurous  and  even  sulfuric  acid. 
In  order  to  insure  purity,  it  is  treated  with  ammonia 
water,  which  neutralises  the  sulfur  acids,  removes 
the  arsenic  which  it  dissolves  out,  and  other  im- 
purities and  produces  a  pure  sulfur.  This  is  known 
as  washed  siiljur,  and  is  preferred  by  many  for 
medicinal  purposes. 

Precipitated    suljur  is  lighter,   more   easily  sus- 
pended in  liquids  and  hence  preferable  to  the  other 
forms.      It  is  prepared  by  boiling  together  sublimed 
sulfur  and  lime,  filtering  and  adding  hydrochloric  acid. 
3CaO  +  3S2  =  2CaS2  +  CaS^Og. 
calcium 
thiosulfate 
2CaS2  +  CaSjOg  +  6HC1  =  3S2  -f  aCaCl^  +  3HO2. 
The  precipitated  sulfur  is  thoroughly  washed  with 
water. 

If  sulfuric  acid  is  used  in  place  of  the  hydrochloric 
acid,  the  precipitate  is  contaminated  with  calcium 
sulfate,  and  it  then  goes  by  the  name  of  "milk"  or 
"lac  sulfur." 

Sulju/  iodid  is  prepared  by  rubbing  together  sulfur 
and  iodin  and  heating..  The  product  is  in  the  form 
of  a  grayish-black  solid  and  is  quite  unstable  and 
decomposes  readily. 


42  I'HARMACEUTIC    CHEMISTRY. 

Compounds. — With  hydrogen : 

Hydros  id j uric  acid,  HjS,  also  called  hydrogen 
sulfid  or  sulfuretted  hydrogen.  A  strong  colorless  gas, 
of  characteristic  odor,  soluljle  in  water,  produced 
naturally  in  organic  decay  when  sulfur  is  present 
Also  found  in  many  mineral  springs.  May  be  pre- 
pared by  acting  on  iron  sulfid  with  dilute  sulfuric 
acid. 

FeS  +  H,SO,  =  H,S  +  FeSO,. 

With  oxygen: 

Sulfur  dioxid,  SO.,  =  sulfurous  anhydrid. 

Sulfur  trioxid,  SO3  =  sulfuric  anhydrid. 

With  oxygen  and  hydrogen: 

H^SOj,    hyposulfurous  acid. 
■    H2SO3,    sulfurous   acid. 

HjSO^,    sulfuric  acid. 

H2S2O3,  thiosulfuric  acid. 

H2S2O7,  pyrosulfuric  acid. 

H^SjOg,  dithionic  acid. 

HjSgOg,  trithionic  acid. 

HjS^Og,  tetrathionic  acid. 

HjSgOg,  pentathionic  acid. 

The  important  ones  arc  sulfuric,  thiosulfuric  and 
pyrosulfuric,  which  will  be  discussed  under  Acids, 
Chapter  VIII. 

PHOSPHORUS. 

Symbol,  P.     At.  wt.,  31.-    Sp.  gr.,  1.83  at. 10°  C. 

History. — Phosphorus  was -discovered  by  Brandt, 
of  Hamburg,  in  1669,  in  urine;  by  Hoyle  in  1680,  b\  a 
secret  process;  in  1769,  by  Gohn,  in  bones;  and  until 


/^   >-^     OF    THE  ^ 

I  UNIVERSITY   I 

1 77 1,  when  Scheele  published  a  method  of  obtaining 
it  from  bone  ash,  phosphorus  was  considered  a  chemi- 
cal curiosity. 

Occurrence. — It  has  never  been  found  free  in  nature; 
in  combination  it  is  most  common  as  calcium  phos- 
phate, Ca3(POj2,  a  mineral  derived  from  the  bones 
of  the  prehistoric  mammals.  Occurs  in  soils  and 
in  animal  bones,  tissue  and  blood.  Also  in  plants 
to  which  it  is  also  essential. 

Properties. — Elementary  phosphorus  is  a  solid 
occurring  in  two  forms:  (i)  Yellow  phosphorus,  soft 
and  flexible,  insoluble  in  water,  soluble  in  oils  and 
carbon  disulfid.  Poisonous,  volatile  and  inflam- 
mable, even  at  low  temperatures,  fusible  and  lumi- 
nous in  the  dark.  Combines  readily  with  oxygen. 
(2)  Red  or  amorphous  phosphorus,  opaque,  in- 
soluble in  carbon  disulfid,  infusible  and  nonlumi- 
nous  and  possessing  no  tendency  to  combine  with 
oxygen.  At  a  temperature  of  260°  C,  it  is  changed 
into  ordinary  phosphorus  and  assumes  its  properties. 
Red  phosphorus  is  prepared  by  heating  the  ordi- 
nary variety  for  about  36  hours  to  a  temperature  of 
250°  C.  without  supply  of  oxygen. 

Other  varieties  have  been  prepared.  The  metallic 
or  black  form  is  prepared  by  heating  red  phosphorus 
in  a  sealed  tube  to  500°  C.  It  is  inert  and  of  no 
importance.  Ordinary  phosphorus  must  be  kept 
under  water  to  prevent  spontaneous  combustion, 
its  most  characteristic  property  being  its  ready 
oxidation. 

Preparation. — Phosphorus  is  obtained   from   cal- 


44  PilARMAtEUTlC    CHKMISTKY. 

fined  bones  by  adding  sullurif  acid,  liltering,  re- 
moving the  calcium  sulfate;  the  liquid  eva[)orated, 
and  residue  distilled  with  charcoal,  thus: 

(i)  Ca3(PO,)2  +  2H,SO,  =  2CaSO,+  CaH,(POJ,. 

calcium  hydrogen 
phosphate. 

(2)  3CaH,(P0,),  +  loC  =  Ca,(PO J-A  +  2P3  + 

6H2O    +    loCO.  ^^•'^^'""^  phosphate 

Compounds. — With  hydrogen : 

PH3,  phosphorus  trihydrid,  phosphoric  or  phos- 
phoretted  hydrogen,  phosphin,  is  a  colorless,  poison- 
ous gas,  inflammable,  odorous,  resembles  ammonia 
to  some  extent  in  its  chemical  properties,  but  is  much 
weaker  in  alkalinity. 

With  oxygen: 

P._;03,  phosphorus  trioxid  or  ])hosphorous  anhy- 
drid. 

P2O5,  phosphorus  pentoxid  or  phosphoric  onhy- 
drid. 

With  oxygen  and  hydrogen: 

Acids  of  phosphorus. 

HPH2O2,  hypophosphorous  acid.      . 

H.,PHO, 

H3PO, 

HPO3,  metaphosphoric  acid. 

(H3PO,  — H,0=HP03). 

H^PgOj,  pyrophosphoric  acid. 

(2H3PO,  —  HjO^H^P-AV 

The  important  acids  are  the  last  three,  all  derived 
from  phosphoric  anhydrid,  thus: 

(i)  P2O5  +  HjO  =  2HPO3,  metaphosphoric  acid. 


BORON.  •  45 

(2)  P2O5  +  2H2O  =  H^PjOy,  pyrophosphoric  acid. 

(3)  P2O5  +  3H2O  =  2H3PO4,  orthophosphoric 
acid. 

The  orthophosphoric  acid  is  the  most  important 
and  is  the  one  meant  by  "phosphoric  acid."  It  is  a 
liquid,  the  other  two  being  solid.  The  meta  acid  is 
known  as  "glacial"  phosphoric  acid. 

BORON. 

Symbol,  B.     At.  wt.,  11.     Valence,  3. 

It  is  never  found  native  in  the  free  state,  but  maybe 
prepared  in  two  allotropic  states,  first  as  a  greenish- 
brown  powder;  second,  as  a  crystalline  solid  of  vary- 
ing colors,  ranging  from  colorless  to  garnet. 

Occurrence. — It  is  found  in  combination  with  cal- 
cium, magnesium  and  sodium  as  borates,  the  latter 
the  most  important,  and  known  as  borax,  is  found  in 
India  and  California.  .As  boric  acid  it  is  found  in 
Tuscany.  Boric  acid  is  prepared  from  the  borate 
bv  the  action  of  hydrochloric  acid,  thus: 
"  Na^B^O;  ioH,6  +  2HCI  =  aNaCl  +  4H3BO,  + 
5H2O'. 

Boric  acid  separates  in  white,  shining  scales,  is  soluble 
in  2  5  parts  of  water  and  3  parts  boiling  water,  is  a  weak 
acid.  A  strip  of  turmeric  paper  dipped  in  a  solution 
of  boric  acid  turns  cherry-red  on  drying. 

Boric  acid  finds  use  as  a  mild  antiseptic  and  deter- 
gent. Boric  acid  and  its  salts  are  poisonous  to 
lower  animals  and  plants  and  have  produced  serious 
conditions  in  human  beings  following  its  use  too 
freelv. 


46  PHARMACEUTIC    CHEMISTRY. 

SILICON. 

Symbol,  Si.     At.  \vt.,  28.     Valence,  2  and  4. 

Occurrence. — Never  found  native,  but  may  be  pre- 
pared in  three  allotropic  states — amorphous,  graphitic 
and  crystalline,  somewhat  resembling  the  three  states 
of  carbon.  This  element,  next  to  oxygen,  is  the  most 
abundant  element  in  nature.  It  is  found  combined 
with  oxygen  as  silica,  Si02,  in  quartz,  sand,  flint  and 
many  minerals.  Clays  are  principally  silicates  of 
aluminum  colored  by  iron  or  other  mineral  or  vege- 
table matter.  Neither  the  element  nor  its  compounds 
are  of  much  interest  to  the  pharmaceutic  student. 

Compounds. — Silicic  hydrid,  SiH4,  also  bromid, 
SiBr^,  and  fluorid,  SiF^,  are  known.  SiO,,  silicic 
oxid  is  the  only  oxid  of  this  element,  known  as 
"silica,"  a  solid,  tasteless,  odorless,  when  freshly 
prepared,  soluble  in  water,  attacked  only  by  hydro- 
fluoric acid,  and  almost  infusible  by  itself.  Found  in 
all  granitic  rocks  which  are  composed  of  quartz, 
feldspar  and  mica.  Quartz  is  almost  pure  silica,  as 
also  are  sands  and  agates,  the  latter  being  a  colloidal 
form  deposited  from  silicious  water.  This  silicious 
water  is  the  chief  agent  in  petrification.  Silica  forms 
the  skeleton  of  certain  invertebrate  animals,  is  found 
in  stems  of  plants,  and  hydrated  it  forms  the  opal. 

When  silica  is  fused  with  alkali  carbonates  or  hy- 
droxids,  it  forms  silicates  with  these  metals  or  a  form 
of  glass,  ihc  most  important  being  the  insoluble 
glass,  silicates  of  sodium,  potassium,  lead  or  calcium  or 
combinations  of  these  wilh  an  exiess  of  silica  present. 


SILICON.  47 

Soluble  glass  is  similarly  made,  but  with  an  excess 
of  the  sodium  or  potassium.  This  product  is  also 
known  as  "water  glass." 

Silicic  acid  may  be  prepared  by  acting  upon  a 
dilute  solution  of  an  alkaline  silicate  with  hydro- 
chloric acid.  It  is  only  found  in  water  solutions  and 
is  very  unstable. 

SELENIUM.— Symbol,  Se.  Valence,  2.  At.  wt., 
78.87. 

TELLURIUM.— Symbol,  Te.  Valence,  2.  At. 
wt.,  125. 

These  elements  are  called  "rare"  and  are  of  little 
importance  to  the  pharmaceutic  student.  They  are 
found  associated  with  sulfur  and  form  acids  similar 
to  sulfurous  and  sulfuric  acids. 


CHAPTER  VI. 
WATER. 

Symbol,  H,0.     Mol.  wt.,  17.96. 

History. — Until  1781  water  was  considered  to  be 
an  element.  At  that  time  Cavendish  proved  its 
composition  by  synthesis.  Priestley  had  also  found 
that  when  hydrogen  and  oxygen  were  combined 
by  explosion  moisture  was  formed,  but  Cavendish 
first  produced  a  sufficient  amount  of  moisture  to 
prove  its  identity. 

In  1805,  Humboldt  and  Guy  Lussac  determined 
the  ratio  of  its  constituents. 

Occurrence. — Water  is  so  widely  distributed  that 
it  may  be  said  to  be  almost  universal. 

It  exists  in  three  states  of  aggregation:  Below 
0°  C,  it  occurs  as  a  solid;  between  0°  C.  and 
100°  C,  it  takes  the  normal  state  of  a  liquid,  and 
above  100°  C,  it  exists  as  a  gas  or  vapor. 

As  gas  we  have  water  vapor  as  a  constituent  of  air 
under  normal  conditions.  The  atmospheric  mois- 
ture is  i)roduced  by  spontaneous  evaporation,  of 
both  the  land  and  water  surfaces;  from  the  forma- 
tion of  steam  in  manufacturing  processes,  respiration 
of  animals  and  plants,  etc. 

Steam  is  gaseous  water  when  first  prepared,  and  at 
a  temperature  above  100°  C.  it  is  colorless  and  in- 
visible, but  is  easily  reduced  in  (emperature.  and 
4S 


WATER.  49 

what  we  ordinarily  speak  of  as  steam  is  a  condensa- 
tion of  the  vapor  forming  very  fine  drojjs  of  water. 
It  is  this  ])artially  or  finely  condensed  moisture  that 
we  see  in  mists,  fogs  and  clouds. 

In  the  liquid  condition,  water  is  present  in  im- 
mense quantities  in  the  ocean,  lakes,  rivers,  smaller 
streams  and  as  rain  and  as  subterranean  waters,  soil 
moisture,  etc.  It  also  occurs,  though  hidden,  as  water 
of  crystallization  in  many  crystals,  minerals,  etc.,  and 
it  is  a  large  constituent  of  all  the  vegetable  and  ani- 
mal organisms. 

Thus,  many  vegetables  are  over  four-fifths  water, 
and  over  three-fourths  the  human  body  consists  of 
water. 

In  the  solid  state,  water  occurs  as  snow,  hail,  and 
ice;  the  two  former  being  modifications  of  the  kil- 
ter. Snow  is,  therefore,  water  congealed  in  the  form 
of  crystals.  Hail  is  an  accumulation  of  layers  of  ice 
formed  to  an  irregular  globe  shape  produced  by 
natural  precipitation  in  certain  atmospheric  currents 
and  ice  is  also  a  crystalline  congealed  water  form. 

At  a  temperature  of  o°  C,  water  changes  under 
normal  conditions  to  a  solid.  As  water  cools  it  con- 
tracts steadily  until  a  temperature  of  4°  C.  is 
reached,  when  it  begins  to  expand  again  until  solidi- 
fication occurs.  Cooling  then  contracts  the  ice 
similarly  to  other  solids.  Ice,  however,  is  lighter 
than  water,  and  hence  rises  or  forms  at  the  surface 
of  the  water.  If  this  were  not  true,  bodies  of  water 
would  freeze  solid,  even  to  the  bottom,  and  lakes, 
streams,  etc.,  would  require  great  time  and  heat  to 
4 


50 


PHARMACKUTU:    CHEMISTRY. 


bring  them  to  the  liquid  state  again.  Water  at  4°  C. 
is  at  its  greatest  density  and  at  that  temperature  is 
taken  as  a  standard  of  weight. 

Water  may  be  classified  as  follows- 


Atmi 


Rain, 
spheric  \  Snow. 

[  Hail,  etc. 


1.  Springs. 

2.  Ground. 


((/)  Sweet  ;  3.  Well 


Terrestrial  • 


f  Open. 
'  Driven. 
[  Artesian. 


(b)   Salt 


4.  Pond  or  Lake. 

5.  River. 

1.  Ocean. 

2.  Inland  Sea. 


Mineral 


Sulfur. 

Saline. 

Acidulous. 

Chalybeate. 

Alkalin. 

Alum  styptic, 

Silicious. 

liorax. 


Water  when  pure  is  a  tasteless  and  odorless  liquid. 
When  seen  in  small  quantities  it  is  colorless,  but  in 
large  masses  it  appears  to  be  of  a  greenish  or  bluish 
color.  This  is  largely  due  to  the  refraction  of  light 
rays,  though  it  is  thought  that  very  finely  divided  sus- 
pended matter  is  also  responsible  for  color  in  waters. 


WATER.  51 

Water  is  a  poor  conductor  of  heat  and  is  only  very 
slightly  compressible.  It  is  the  most  important 
solvent  and  dissolves  a  larger  number  of  substances 
than  any  other  liquid.  Owing  to  this  property,  no 
natural  waters  are  found  to  be  strictly  pure,  for  even 
rain  water  contains  foreign  materials  dissolved  as  the 
rain  passes  through  the  air. 

Atmospheric  waters.  Rain  water,  as  stated,  is 
impure  and  may  contain  more  or  less  of  the  follow- 
ing impurities:  dust,  germs,  oxygen,  nitrogen,  carbon 
dioxid  and  ammonia  from  the  air  of  which  they  are 
constituents.  Nitric,  nitrous  and  sulfuric  acids  or- 
ganic substances,  saline  matter,  ozone  and  hydrogen 
peroxid  in  very  small  amounts  are  also  found. 

In  spite  of  this  number  of  possible  contaminating 
materials,  rain  water  is  the  purest  form  of  natural 
water  and  may  contain,  if  collected  in  the  country,  an 
average  of  about  0.029  parts  of  foreign  matter  in  1000 
parts  of  water.  Collected  in  towns  or  cities,  much 
larger  quantities  are  present. 

Rain  water  after  reaching  the  earth  becomes  at 
once  contaminated  with  various  matters,  depending 
upon  the  surface  upon  which  it  falls  and  the  strata  over 
or  through  which  it  may  flow.  It  reappears  as  ter- 
restrial water  and  will  be  so  considered. 

First,  spring  water.  Is  always  chemically  impure, 
the  nature  and  quantity  depending  upon  the  locality 
and  constituents  of  the  soil,  through  which  it  passes. 
Generally  clear,  cool  and  sparkling  and  hence 
potable. 

It  usually  contains   (i)   Chlorids,  sulfates,  bicar- 


52  J'HARMAC-EUTIC    ClIKMISTKY. 

bonates  of  ]H)tasbium,  sodium,  calcium  and  magne- 
sium. (2)  Ncarlyalways  silica  and  traces  of  aluminum 
and  iron.  (3)  The  atmospheric  contamination  ma- 
terial before  mentioned.  (4)  Organic  decomposition 
matter  and  bacteria  usually  harmless  in  nature. 

A  property  more  common  to  sj^ring  water  than  to 
other  waters  is  hardness.  This  may  be  defined  as 
that  ])ropcrly  of  water  which  renders  the  formation 
of  a  lather  with  soa})  difficult.  It  is  due  largely 
to  salts  of  lime,  but  also  to  salts  of  magnesium  and 
iron.  If  these  salts  consist  of  carbonates  which 
can  be  removed  by  boiling  it,  the  hardness  is  known 
as  "  Temporary."  If  due  to  sulfates,  however,  boil- 
ing will  not  remove  them,  and  it  is  then  known  as 
' '  Permanent "    Hardness. 

The  incrustations  forming  in  boilers,  etc.,  are  ])ro- 
duced  by  the  deposition  of  these  mineral  constituents. 
Temporary  hardness  crusts  can  be  removed  b}- 
ammonium  chlorid,  which  converts  the  bicarbon- 
ates  into  readily  soluble  chlorids.  Crusts  produced 
by  permanently  hard  waters  are  not  affected  by 
the  ammonium  chlorid.  Numerous  boiler  com- 
pounds are  on  the  market  for  this  i)urf)ose,  the  best 
of  which  is  trisodium  phosphate,  Na^PO^. 

Ground  water  is  water  held  by  the  porous  strata 
of  the  earth's  surface  as  far  as  the  first  impervious 
layer,  and  has  the  same  properties  as  the  well  waters. 

Well  Wafer. — Well  waters  arc  of  three  types  as 
stated.  Thus  we  have  the  ()])en  or  dug  well,  the 
driven  or  drilled  well  and  the  artesian  well.  The  first 
class    is    supplied    with    water     from    sul)lerranean 


springs  or  streams  or  from  surface  drainage.  From 
the  former  source  the  water  may  contain  the  materials 
enumerated  under  spring  water.  The  surface  water 
supply  may  contain  salts  and  nitrogenous  matter 
from  house  drainage,  also  possible  sewage  from  vaults 
and  cesspools. 

The  much-applauded  country  well  water  may,  un- 
less much  care  is  taken  in  its  location,  with  relation 
to  buildings,  cesspools,  vaults,  etc.,  be  a  concentrated 
liquid  full  of  infection  and  filth. 

Driven  wells  come  in  for  similar  criticism,  and 
much  care  should  be  exercised  in  selecting  their 
location. 

Artesiin  or  deep  strata  wells  are  usually  free  from 
surface  and  organic  impurities,  but  often  are  very 
heavily  laden  with  mineral  matter,  and  may  thus 
be  rendered  unfit  for  potable  purposes.  Artesian 
wells,  of  course,  can  be  obtained  only  in  places  where 
the  strata  so  slope  as  to  form  a  deep,  impervious 
basin  at  the  center  of  which  the  well  is  drilled. 

Pond,  Lake  and  River  Waters. — These,  generally 
speaking,  are  purer  waters,  naturally,  than  spring 
waters.  Suspended  matters  are  present  in  running 
water,  but  when  the  water  comes  to  rest  these  matters 
are  dcfju.'^ited  as  sediment  and  the  water  becomes 
clear. 

Streams  however,  flowing  through  populous  dis- 
tricts, often  become  contaminated  with  sewage,  and 
when  used  as  outlets  for  city  refuse,  sewage,  manu- 
facturing waste,  etc.,  they  become  offensive  and 
dangerous    for    potable    purposes.     These    organic 


54  PHARMACEUTIC    CHEMISTRY 

matters,  however,  soon  liecome  oxidized  with  the 
oxygen  held  by  the  water  itself,  by  the  oxygen  of 
the  air  and  the  effect  of  sunlight,  and  by  action  of 
bacteria  present,  and  hence  are  rendered  harmless. 
Flowing  streams  are  supposed  to  purify  themselves 
in  from  8  to  12  miles,  dependent  upon  the  nature  of 
their  beds  and  the  rate  of  flow.  This  is  doubted 
by  some  authorities,  however,  and  it  is  still  an  open 
question. 

Ocean  and  Inland  Sea  Waters.— T\\t  water  of  the 
ocean  contains  a  large  amount  of  sodium  chlorid  and 
magnesium  chlorid,  some  potassium,  calcium  and 
magnesium  sulfates,  sodium  bromid  and  traces  of 
other  salts.  The  total  average  amounts  to  about 
2138  grains  (138  gms.)  per  gallon,  of  which  about 
80%  is  sodium  chlorid  (common  salt).  Inland  seas 
contain  much  larger  amounts— the  Dead  Sea  about 
six  times  and  Great  Salt  Lake  seven  times  as  much 
solids  as  the  ocean.  They  also  contain  several  salts 
not  found  in  ocean  water  but  due  to  the  nature  of 
the  soil  drained  into  them.  Potassium  chlorid  and 
calcium  chlorid  are  examples. 

Mineral  Waters  are  natural  waters  which  con- 
tain unusually  large  quantities  of  some  of  the  or- 
dinary impurities  or  are  characterized  by  unusual 
constituents;  they  are  named  according  to  their 
most  prominent  characteristics,  thus: 

(i)  Sulfur  water  contains  sulfur  in  form  of  hydro- 
gen sulfid,  metallic  sulfids  or  even  free  sulfur.  They 
usually  also  contain  other  salts.  The  odor  of  sul- 
furetted    hydrogen     is    nearly    always    noticeable. 


WATER.  ■      55 

Examples:  Harrowgate,  of  England,  White  Sulfur, 
of  Virginia,  and  others  throughout  the  United  States. 

(2)  Salines,  those  having  a  salty  taste,  are  of  three 
classes:  (i)  Brines,  in  which  sodium  chlorid  pre- 
dominates, but  usually  also  contain  sodium  bromid 
and  iodid.  Examples,  salt  wells  of  Michigan  and 
springs  at  Syracuse,  N.  Y.  (2)  Bitter,  waters,  con- 
taining calcium  and  magnesium  chlorids,  as  St.  Cath- 
erine Spring,  Canada.  (3)  Purgative  waters,  contain- 
ing magnesium  or  sodium  sulfates,  as  Epsom  Spring 
or  Kissingen. 

Acidulous  waters  contain  sufficient  free  carbonic 
acid  gas  to  produce  effervescence,  as  appolinaris, 
selters,  etc. 

Chalybeates  are  those  with  iron  present  in  medic- 
inal quantities,  usually  in  the  form  of  bicarbonate 
or  sulfate. 

Alkalin  waters  are  not  alkalin  when  fresh,  but 
if  boiled  the  bicarbonates  are  changed  to  carbonates. 
Other  salts  generally  present.  Examples:  Saratoga 
and  Vichy  waters. 

Acid  waters  are  those  containing  free  acids,  such 
as  hydrochloric  or  sulfuric.  Rio  Vinaigre,  of  South 
America,  contains  both. 

Alum  waters  contain  alum,  also,  generally,  sulfuric 
acid  and  iron.  Rockbridge  and  Church  Hill  Alum 
Springs,  both  of  Virginia,  are  examples. 

Silicious  wa  ers  are  those  containing  considerable 
silica,  usually  hot  springs.  Geysers  of  Iceland  are 
examples. 

Borax  waters  contain  borax  in  quantities  profitable 


56  i'llAftMACKlTIC    rnKMlSTKY. 

to  extract.  Certain  lakes  of  Thibet  and  California 
come  under  this  class. 

Artificial  mineral  waters  if  well  made  are  of  much 
medicinal  value,  but  often  nearly  pure  spring  waters 
are  sold  as  mineral  waters  and  really  have  no  such 
value. 

Potable  waters  are  those  that  are  suitable  for 
drinking  purposes,  and  since  these  are  of  such  great 
importance  to  man  and  since  it  has  also  been  proven 
that  waters  are  a  fruitful  source  of  supply  of  infec- 
tious diseases,  it  is  essential  that  waters  used  for 
drinking  purposes  be  as  pure  as  possible.  No  natural 
waters  are  pure.  Pure  water  may  be  obtained  by 
distillation,  by  rejecting  the  lirst  and  last  ten  per 
cent,  distilled,  but  even  this  is  not  the  best  potable 
water.  For  the  best  sustenance  of  the  body  a  potable 
water  should  contain  a  trace  of  magnesium  and 
calcium  salts. 

As  a  general  thing,  small  amounts  of  mineral 
matters  are  not  injurious  to  health;  and  organic 
matter  in  itself  is  not  always  certainly  harmful,  but  it 
usually  does  show  sewage  or  other  contamination 
which  might  easily  carry  with  it  bacterial  growths  that 
could  produce  disease  conditions.  Chemical  analysis, 
it  is  true,  cannot  prove  bacteria  present,  but  it  can 
show  the  constants  which,  if  large,  go  to  indicate  prob- 
able contamination  and  by  this  means  lead  to 
further  investigation.  Suspicious  waters  should 
always  be  refused  and  thorough  examination  of 
their  source,  chances  of  c(jntamination,  etc.,  made. 
Waters    may    be    purified    by    numerous  methods: 


I'OTABLK    WATER.  57 

On  the  large  scale  by  open  sand  filtration  beds  or  by 
the  later  percolation  spray  system.  In  small  house- 
hold quantities  by  types  of  porous  porcelain  or  char- 
coal filters,  etc.  Space  will  not  allow  of  detailed 
discussion. 

Usual  types  of  waters  called  potable  may  be  classi- 
fied thus: 


Safe 

Suspicious 
Dangerous 


1.  Spring  waters. 

2.  Deep  well  waters. 

3.  Mountain  lake  or  river  waters. 

1.  Stored  rain  water. 

2.  Surface  water. 

1.  River  water  with  sewage. 

2.  Shallow  well  water. 


Sewage  is  always  dangerous,  due  to  the  liability  of 
pathogenic  bacteria  being  present. 

Refuse  from  factories  is  usually  not  dangerous 
in  running  streams,  for  the  poisonous  materials 
either  neutralize  each  other  or  are  sufficiently  diluted 
to  render  them  harmless. 

Metallic  impurities  usually  are  derived  from  pipes 
or  tanks.  Copper  has  been  known  to  produce  sick- 
ness. The  most  common  form  of  sickness  is  lead 
poisoning.  This  is  produced  by  the  solvent  action 
of  the  water,  also  of  the  dissolved  carbon  dioxid  on 
the  leaden  pipes.  Water  that  has  stood  for  some 
hours  in  the  leaden  pipes  should  never  be  used  for 
drinking. 

Water  may  be  examined  for  probable  purity  or 
contamination  as  follows:     By  noticing  the  taste, 


58  PHARMACEI'TIC    CHEMISTRY. 

(xlor,  reaction,  turlndily  and  color.  It  should  he 
negative  in  all  these  res})ects. 

Total  residue  is  ohtained  by  evaporating  a  known 
quantity  to  dryness.  Dissolved  solids,  by  filtering, 
evaporating  and  weighing.  It  may  reach  30-50 
grains  per  gallon  safely. 

Non-volatile  residue  is  obtained  by  igniting  the 
total  residue.  The  loss  on  ignition  shows  organic 
constituents  and  should  not  be  50%  of  the  total 
residue. 

Hardness  determined  by  Clark's  test,  which  con- 
sists in  using  a  standard  soap  solution  to  make  a 
lather  with  the  water.  Small  quantities  are  added 
with  agitation  ui.til  the  lather  persists  for  five 
minutes.  A  blank  teit  must  be  carried  out  with 
distilled  water.  A  water  containing  not  over  50 
parts  per  million  of  "hardness"  is  classed  as  a  soft 
water,  one  with  150  parts  is  a  hard  water. 

Chlorin  is  detei  mined  by  the  use  of  standard  silver 
nitrate  solution.  One  hundred  cubic  centimeters 
of  the  w-ater  is  placed  in  a  white  porcelain  dish, 
a  few  drops  of  potassium  chromate  indicator  added 
and  silver  nitrate  solution  run  in  from  a  burette,  drop 
by  drop,  till  a  slight  red  tint  appears.  If  chlorin  is 
present  in  very  small  amounts  the  water  may  be  re- 
duced to  one-half  its  bulk  by  evaporation  before 
titration.  Too  much  dependence  should  not  be 
placed  upon  amount  of  chlorin  present,  for  larger 
amounts  of  organic  matter  may  be  present  and  very 
little  chlorin  be  fou-nd.  Also  high  chlorin  present 
may  be    due    to    dissolved    chlorids   from  the  soil, 


WATER- ANALYSIS.  59 

hence  the  characteristics  of  surroundings  should  be 
taken  into  account  in  the  consideration  of  potability. 
Sewage  generally  contains  about  ii  parts  per  100,000, 
and  if  conditions  do  not  give  reasons  for  high  chlorin, 
over  5  parts  per  100,000  may  be  considered  suspi- 
( ious  of  sewage  contamination. 

Sulfates  are  determined  by  precipitation  as  barium 
chlorid.  Nitrites,  by  add  ng  sodium  sulfanilate  and 
sulfuric  acid,  then  naphthylamin.  Nitrites  will  de- 
velop a  pink  color,  the  depth  dependent  upon  the 
quantity  of  the  nitrites  present. 

Nitrates,  a  simple  qualitative  test  may  be  made, 
using  diphenylamin  in  concentrated  sulfuric  acid. 
A  deep  blue  indicates  nitrates  or  nitrites.  Quantita- 
tively, nitrates  may  be  tested  by  using  sulfanilic  acid 
and  naphthylam.in  hydrochlorid. 

Free  ammonia  is  determined  by  use  of  Nessler's 
reagent  in  standard  tubes  for  reading  the  color  pro- 
duced. Ammonia  also  exists  combined  and  known  as 
albuminoid  ammonia.  Water  is  first  made  alkalin 
with  fixed  alkali  and  distilled;  the  result  is  the 
amount  of  free  ammonia.  Permanganate  of  potas- 
sium is  now  added  to  the  retort  and  further  portions 
distilled  over.  The  permanganate  breaks  down  the 
albuminoids  and  ammonia  is  formed,  which  is 
distilled  over  and  Nesslerized.  A  good  water  should 
not  contain  more  than  o.i  parts  of  free  ammonia  or 
0.15  of  albuminoid  ammonia  in  one  million  parts  of 
water  examined. 

Organic  matter  is  determined  by  the  oxygen 
consuming     power    as    measured   by   the   amount 


6o  IM1A1<MA(^KUT1C    CIl  KMISTK  Y. 

of  potassium  permanganate  consumed  in  its 
oxidizing. 

The  mineral  constituents,  calcium,  magnesium, 
etc.,  are  readily  determined  by  regular  methods. 

Bacteriologic  examinations  of  water  are  very 
essential  to  a  thorough  understanding  of  its  purity, 
and  I  c.c.  of  the  water  is  placed  in  a  shallow  dish 
with  lo  c.c.  of  sterilized  beef  extract  as  gelatin; 
covering  carefully  and  allowing  the  bacteria  to 
produce  colonies.  These  colonies  after  a  few  days 
may  be  counted  and  each  colony  represents  an  in- 
dividual original  bacteria.  The  study  of  the  variety 
of  colonies  may  be  carried  as  far  as  is  desired. 

Chemical  analysis  cannot  always  tell  more  than 
whether  the  water  is  contaminated  or  not,  but  with 
this  as  a  guide  we  can  carry  our  bacteriologic  work  as 
far  as  we  please  and  prove  the  presence  or  al^sence 
of  pathogenic  bacteria. 

In  choosing  potable  waters  from  wells,  springs,  etc., 
care  must  be  taken  that  cesspools,  privies,  manure 
piles  and  stable  or  kitchen  refuse  is  not  within  loo 
feet  at  least  of  the  source  of  supply,  and  a  study  of 
the  strata  of  the  soil  is  valuable.  ■  If  organic  contami- 
nation is  found,  the  only  safe  thing  is  to  reject  the 
water  entirely.  An  understanding  of  conditions  is 
quite  necessary  besides  the  chemical  or  bacteriologic 
examination. 


CHAPTER  VII. 
THE  ATMOSPHERE. 

This  name  is  applied  to  the  gaseous  mixture  that 
envelops  the  earth.  It  is  commonly  called  the  air. 
The  air  is  very  elastic  and  hence  is  much  denser  near 
the  earth  and  exerts  at  sea  level  a  pressure  of  about 
fifteen  pounds  to  the  square  inch.  It  becomes  grad- 
ually lighter  the  farther  away  from  the  earth's  surface 
and  is  thought  to  cease  entirely  at  about  twenty 
miles.      One-half  is  contained  in  the  first  three  miles. 

The  air  consists  of  a  mixture  of  gases,  of  which 
oxygen  is  the  most  important  and  nitrogen  the  most 
abundant.  Lavoisier  was  first  to  definitely  prove 
the  presence  of  oxygen  in  the  air,  but  Boyle,  Priestley 
and  Cavendish  all  had  a  part  in  its  early  investiga- 
tion. 

The  air  is  proven  to  be  a  mixture,  not  a  com- 
pound, by  the  facts  that,  first,  an  artificial  air  can  be 
made  by  mixture  only;  secondly,  the  gases  are 
not  present  in  quantities  represented  by  their  atomic 
weights;  thirdly,  solvents  of  one  gas  dissolve  it 
without  reference  to  the  others.  It  is  a  remarkably 
constant  mixture,  however,  and  hundreds  of  analy- 
ses showed  an  amount  of  oxygen  varying  only  from 
20.90%  by  volume  to  20.99%  '^7  volume.  One 
liter  of  air  at  normal  conditions  weighs  1.293  g"^s. 
One  hundred  cubic  inches  weigh  31  grains.  It  is 
61 


779 

oo 

2o6 

.6 

M 

.00 

o 

•34 

o 

.008 

o 

.0015 

o 

.0005 

62  PHAR.\IACi:UTIC    CHEMISTRY. 

14.44  times  as  heavy  as  hydrogen.     Gerccke  was  first 
to  determine  the  weight  of  air. 

The    average    composition     in    parts    per    1000 
volumes  may  be  said  to  be: 

Nitrogen, 

Oxygen. 

Aqueous  vapor, 

Carbon  dioxid 

Ammonia, 

Ozone, 

Nitric  acid, 

Argon,  hydrogen  peroxid,  sul- 
furic acid,  etc.,  mere  traces. 
The  essential  constituents  are  oxygen,   nitrogen, 
carbon  dioxid  and  water  vapor,  the  others  being  in 
very  small  amounts  or  occur  as  impurities  and  hence 
require  no  special  discussion. 

Animal  life  is  constantly  taking  up  oxygen  and 
giving  off  carbon  dioxid.  Vegetable  life,  however, 
takes  up  carbon  dioxid  and  gives  up  oxygen,  hence 
the  balance  is  sustained.  Air,  as  stated  above 
always  contains  about  such  a  ratio  of  oxygen  and 
of  nitrogen,  and  not  much  of  the  nitrogen  of  the 
air  is  consumed  as  such.  Nitrates  and  nitrites  occur 
occasionally  due  to  direct  union  of  nitrogen  and  oxy- 
gen, especially  under  influence  of  lightning  flashes. 
Water  vapor  or  moisture  in  the  air  is  very  variable, 
the  amount  depending  upon  the  temperature  and 
locality.  Saturated  air  is  air  holding  all  the  vapor 
that  it  is  capable  of  holding  at  a  given  temper- 
ature.    Warm   air  will   hold    much   more  moisture 


AIR.  63 

than  cold  air,  thus  air  may  be  saturated  at  25° 
C;  but  if  warmed  to  50°  C,  seems  quite  dry,  hence 
precautions  should  be  taken  to  keep  the  air  of  living 
apartments  properly  moist,  even  if  warm.  If  too 
dry,  air  is  irritating  to  mucous  membranes,  but  if 
too  moist  is  oppressive  by  checking  perspiration  and 
raising  body  temperature.  A  very  damp  air  also 
favors  bacterial  growth. 

The  dew  point  is  known  as  the  temperature  at 
which  the  air  begins  to  deposit  its  moisture.  The 
percentage  of  humidity  in  meteorology  means  the 
ratio  between  the  amount  of  moisture  present  and 
that  necessary  to  saturate  the  air  at  the  give.i  temper- 
ature. One  cubic  foot  of  air  at  25°  C.  will  be  satu- 
rated by  about  10  grains  of  water  vapor,  but  it 
seldom  contains  over  about  70%  of  the  amount 
required  for  saturation. 

Carbon  dioxid  is  present,  due  to  combustion,  res- 
piration, etc.,  and  in  closely  populated  places  the 
quantity  increases  largely.  In  poorly  ventilated  and 
crowded  rooms  it  rises  very  high.  In  the  country 
it  is  found  only  in  about  4  parts  per  io,ooo.  Plants 
remove  it  from  the  air  during  the  day,  hence  it  is  not 
so  high  in  per  cent,  by  day  as  by  night. 

Ammonia,  nitrous  and  nitric  acids,  hydrogen  per- 
oxid,  sulfuric  acid,  etc.,  are  due  to  decomposition  of 
organic  nitrogenous  matter,  direct  chemical  reaction 
or  direct  union  of  the  air  constituents. 

The  air  always  contains  gome  solid  impurities, 
such  as  dust,  clay  and  sand,  some  mineral  salts,  frag- 
ments of  animal  and  vegetable  tissues  and  refuse  and 


64  PHARMACEUTIC    CHf:MISTRY 

living  bacterial  products,  moulds,  yeast,  other  bac- 
teria and  their  germs.  This  latter  class  of  products 
produce  moulds,  decay,  fermentations,  and  some 
even  produce  disease.  Plant  pollen  often  produces 
hay  fever,  and  other  foreign  matter  may  produce 
irritation  of  mucous  membranes,  lungs,  etc.  In 
living  apartments  modern  conveniences  require  the 
use  of  toilet  equipment  and  these  should  be  properly 
constructed  in  order  to  prevent  contamination  of  the 
air  we  breathe. 

Sewer  gas  contains  methane  and  carbon  dio.xid 
largelv,  but  also  hydrogen,  nitrogen,  ammonia  and 
acids  and  sulfur  compounds,  the  latter  usually  caus- 
ing the  disagreeable  odors  noticed.  It  is  not  the 
gases  that  are  productive  of  disease,  but  the  bacteria 
wh'ch  may  be  spread  into  the  air.  To  prevent  entrance 
of  the  foul  odors  and  dangerous  bacteria,  proper 
plumbing  should  be  installed.  The  soil-pipe  and 
trap  connections  should  open  by  a  pipe  through 
the  roof  of  the  house;  the  soil-pipe  should  be  a 
4-inch  iron  pipe  and  throughout  its  extent  insure  a 
flow  of  at  least  four  and  one-half  feet  per  second. 
The  traps  should  be  siphon  filling  Straps  so  as  to 
be  always  automatic  in  lilling,  and  the  closets  should 
be  connected  with  the  flush-box  only— not  with  the 
large  house  tank,  if  such  is  used.  A  properly  in- 
stalled toilet  will  not  give  out  any  offensive  odors 
and  will  be  perfectly  sanitary  if  j^ropcrly  cleansed 
and  cared  for. 

Ground  air,  pioduicd  by  dcconii)()si(ii)n  of  or 
ganic   matters,   is  found  in   soil   as  far  down  as  the 


VENTILATION.  65 

water  level.  In  cellars,  etc.,  this  air  sometimes 
collects  and  may  be  dangerous  from  its  contamina- 
ting bacteria.  The  cellar  floors  and  walls  should 
be  sealed  by  the  use  of  pitch  or  other  impervious 
materials. 

The  carbon  dioxid  of  living-rooms  is  not  always 
poisonous  if  it  should  come  from  other  sources  than 
respiration,  organic  decay,  etc.,  but  since  this  is  the 
ordinary  source  in  living  apartments,  proper  means 
should  be  taken  to  remove  the  foul  air  and  supply 
fresh,  out-door  air.  Each  human  adult  requires 
about  3000  feet  of  air  per  hour.  This  will  re- 
quire 1000  feet  of  air  space,  for  air  cannot  well  be 
changed  oftener  than  three  times  an  hour  without 
undesirable  air  currents. 

Modes  of  ventilation  may  be  divided  into  (i) 
natural  and  (2)  artificial.  Natural  methods  depend 
upon  (i)  diffusion,  which  is  of  little  service;  (2)  dif- 
ference in  density  between  warm  and  cold  air:  warm 
air  rising  and  driving  cold  air  in  at  a  lower  level; 
(3)  the  perflating  and  aspirating  action  of  the  wind. 
The  fact  that  air  currents  will  pass  through  small 
crevices  in  windows  and  walls  produces  a  cross 
ventilation  of  a  mild  type.  Care  should  be  taken 
not  to  produce  decided  draughts,  and  numerous 
devices  may  be  arranged. 

The  aspirating  power  is  seen  when  wind  blows  over 
a  chimney  top:  it  displaces  the  air  near  the  top,  that 
lower  down  moves  up  to  take  its  place,  and  thus  the 
draught  up  the  chimney  is  established.  Heated  air 
upon  rising  in  the  chimney  serves  to  assist  this  power. 


66  I'lTARMACEUTIC    CUKMISTRY. 

Fans  are  also  used  to  force  air  out  or  into  a  room, 
but  usually  do  little  more  than  stir  up  the  same  air 
constantly.  A  reasonable  amount  of  care  in  chimney 
construction  and  placing  of  windows  usually  produces 
good  results;  but  if  not,  many  commercial,  scien- 
tifically built  systems  of  ventilation  may  be  obtained. 
Sources  of  pollution  of  air  we  breath  are:  factories, 
putrefaction,  ground  air,  respiration  of  animals  and 
combustion  in  its  multiple  forms. 


CHAPTER  VIII. 
ACIDS. 

An  acid  is  usually  defined  as  a  substance  contain- 
ing hydrogen  which  is  easily  replaced  by  a  metal. 
Acids  are  also  defined  as  salts  of  hydrogen 

Acids  have  some  properties  in  common,  as  (i)  all 
contain  hydrogen,  (2)  when  a  metal  and  an  acid  are 
placed  together,  hydrogen  is  liberated  and  a  salt 
formed;  (3)  they  usually  change  vegetable  colors; 
(4)  they  usually  have  a  sour  taste. 

Acids  are  divided  into  classes  according  to  the 
number  of  replaceable  hydrogen  atoms  the  molecule 
of  the  acid  holds,  thus: 

Monobasic  acids  have  but  one  hydrogen  atom  re- 
placeable.    Example,  hydrochloric  acid,  HCl. 

Dibasic,  tribasic,  tetrabasic,  etc.,  contain,  respect- 
ively, two,  three  and  four  replaceable  hydrogens. 

The  basicity  of  acids  allows  the  formation  of  nor- 
mal and  acid  salts,  a  normal  salt  being  produced 
when  all  available  hydrogens  are  replaced;  an  acid 
salt  being  one  in  which  not  all  of  the  replaceable 
hydrogen  has  been  replaced.  Acids  are  made  up 
generally  of  hydrogen,  a  nonmetallic  element,  and 
may  or  may  not  contain  oxygen.  When  it  does  not 
contain  oxygen  it  is  called  a  hydracid,  and  has  the 
prefix  "hydro"  and  the  termination  "ic";  thus, 
HCl  =  hydrochloric  acid.  The  class  is  comparatively 
small.  When  oxygen  is  present  they  are  known  as  the 
67 


68  PHARMACEUTIC    CHEMISTRY. 

oxacids.  The  best  known,  normal,  or  most  im- 
portant acid  is  generally  without  prefix,  but  ends  in 
"ic,"  as  sulfuric  acid,  H2SO4.  If  another  con- 
tains less  oxygen,  this  has  the  suffix  "ous."  Some 
elements  form  acids  with  still  less  oxygen.  The 
prefix  "hypo"  (meaning  below)  is  used,  and  also  the 
ending  "ous."  If  the  same  element  forms  an  acid 
of  greater  oxygen  content  than  the  "ic"  acid,  the 
prefix  "per"  (meaning  more)  is  applied  and  also 
retains  the  suflix  "ic."  Acids  may  be  solid,  liquid 
or  gaseous,  or  solutions  of  each. 

They  occur  both  naturally  weak  or  strong  in  acid 
properties,  and  both  concentrated  and  dilute  depend- 
ent upon  their  purity  and  dilution  with  a  solvent, 
usually  water.  Each  acid  in  addition  to  the  general 
acid  properties  also  has  its  own  special  properties 
differing  from  the  others,  and  these  will  be  taken 
up  under  the  acids  themselves.  According  to  their 
basicity,  the  following  list  of  important  acids  is  ar- 
ranged. 

Nitrous  Acid,  HNO,  =  H  —  ()  —  N  =  O. 
Not  known  in  the  pure  state,  but  it  exists  in  solution, 
and  a  number  of  its  salts  are  in  common  use.     Ii  may 
be  i)repared  by  passing  nitrous  anhydrid  (trioxid) 
into  water. 

N./),  +  H,,()  =  2HN(),. 
Tile  salts  ma\-  be  |)repared  by  heating  nitrate^-. 

KNO3  -f-  heat  =  KNO,  +  O. 
Usually  some  readily  oxidizable  substance  is  added, 
thus: 

KNO,  +  Vh  +  heat  =  KNO,  -h  PbO. 


ACIDS    OF    NITROGEN.  69 

In  nature,  the  nitrites  are  produced  by  the  oxidation 
of  nitrogenous  organic  matter;  this  occurs  in  water 
and  soils. 

Nitric  Acid  HNO3  =  H  —  O  —  Nf     . 

Known  as  aqua  fortis  (strong  water).  A  colorless 
liquid,  pungent,  very  acid  taste  and  gives  ofif  red 
fulnes  when  heated.  Very  corrosive,  staining  the 
skin  yellow,  and  forms  picric  acid  applied  to  the  skin. 
Prepared  by  acting  on  a  nitrate  with  sulfuric  acid,  thus : 

NaNOj  +  H2SO,  =  KHSO,  +  HNO3. 
Its  specific  gravity  is  1.52,  strength  68%  when  pure, 
boils  at  86 °  C.  and  solidifies  at  40 °  C.  When  heated 
it  is  decomposed  into  nitrogen  tetroxid,  water  and 
oxygen.  It  gives  up  part  of  its  oxygen  so  readily 
that  it  acts  as  a  strong  oxidizing  agent.  It  acts 
readily  upon  most  metals,  producing  salts,  and  upon 
nonmetals,  oxidizing  them.  All  nitrates  are  soluble 
in  water.  Aqua  regia — Nitrohydrochloric  acid  is 
prepared  by  mixing  four  parts  of  hydrochloric  and 
one  part  nitric  acid,  and  has  the  property  of  dis- 
solving gold,  platinum  and  other  refractory  metals. 
Fuming  nitric  acid  is  a  reddish-brown  liquid  con- 
taining dissolved  nitrogen  trioxid  or  tetroxid,  and  is 
a  powerful  oxidizing  agent. 

Hydrocyanic  acid,  HCN  =  H— HCN  =  H  —  C  =  N, 
called  prussic  acid,  is  best  prepared  by  decomposing 
metallic  cyanids  with  hydrochlor'c  acid,  thus: 

AgCN  +  HCl  =  AgCl  +  HCN 
It  boils  at  26.5°  C,  is  soluble  in  water.     Is  a  colorless 


yo  I'llARMACKUTIC    CHEMISTRY. 

liquid  with  ven-  characteristic  odor  and  taste,  famil- 
iar to  us  as  the  odor  of  oil  of  bitter  almonds,  which 
contains  considerable  of  the  acid.  It  is  very  poison- 
ous, and  since  it  volatilizes  very  readily  from  solu- 
tion or  salt  compounds  of  hydrocyanic  acid,  should 
be  handled  very  carefully.  The  dilute  hydrocyanic 
acid,  U.  S.  P.,  contains  2%  of  HCN. 

H 

i        • 
Hxpo phosphorous  Acid,  H3PO,  =  H  —  O  —  P  =  0. 

I 
H 

A    syrupy,  colorless,  strongly  acid  liquid,  unstable, 

readily    oxidizing    to  phosphorous  and  phosphoric 

acids.     The  acid  is  30%  strong,  and  is  not  largely 

used,  but  the  salts,  called  hypophosphites,  are  of 

considerable  value.      Acid  hypophosphorous  dilute 

is  a  10%  solution  of  acid,  it  is  a  colorless,  odorless 

liquid,  miscible  with  water.      It  is  changed  by  high 

heat  to  phosphoric  acid  and  phosphin.    May  be  tested 

by  silver  nitrate,  which  it  reduces  to  metallic  silver. 

M  eta  phosphoric  Acid,  HPO3,  H  —  O  —  (P^     ). 

Called  glacial  phosphoric  acid,  and  occurs  as  a  white, 
glassy,  colorless  solid.  Forms  salts  known  as  meta- 
phosphates,  as  sodium  metaphosphate,  NaPOj. 
Usually  the  acid  is  prepared  by  heating  ammt)nium 
phosphate   thus: 

(NHJ3PO,  +  heat  =  3NH3  +  H2O  -h  HPO3. 

Hydrochloric  Acid,  HCl  =  H  —  CI. 

Hvdrogen    chlorid,   muriatic    acid    "spirit   of    salt." 


ACIDS    OF    CHLORIN.  71 

Occurs  but  little  in  nature,  but  is  found  in  volcanic 
gases  and  in  gastric  juices  of  mammals.  It  is  a 
colorless,  invisible  gas,  with  a  pungent,  penetrating, 
irritant  odor,  a  sharp,  acid  taste  and  acid  reaction. 
It  is  irrespirable  and  does  not  burn  or  support  com- 
bustion; very  soluble  in  water,  and  its  solution  forms 
the  customary  acid  of  commerce.  One  volume  of 
water  contains  450  volumes  of  the  gas.  It  has  a 
specific  gravity  of  1.21,  and  contains  about  32'%  of 
the  acid.  The  pure  gaseous  acid  may  be  reduced  to 
a  liquid  at  10°  C.  with  40  atmospheres  of  pressure. 
The  U.S.  P.  acid  is  a  fuming  liquid  of  31.9% 
strength;  specific  gravity  at  25°  C.  is  1. 158.  Dilute 
hydrochloric  acid  U.  S.  P.  should  contain  10%  of 
acid;  has  a  specific  gravity  of  1.050  at  15°  C. 

Nitromuriatic  Acid  U.  S.  P.   (see  Aqua  Regia), 
180  parts  HNO3  +  820  parts  HCl,  reacts  thus: 
HNO3  +  3HCI  =  NOCI2  +  2H2O  +  CI. 
HNO3  +  3HCI  =  NOCl   +  2H,0  +  2CI. 
Derfves  the  name  aqua  regia  because  it  will  dissolve 
gold,  the  king  of  metals. 

Hypochlorousacid,HC10  =H— O— CI. 

Chlorous  acid,         HC102  =  H— O— O— CI. 

Chloric  acid,  HC10,  =  H— O— (O— O— CI). 

Perchloric  acid,  HC10,  =  H— O— (O— O— O— 
CI). 

Bromin  and  iodin  form  similar  series  to  the  above, 
but  all  are  of  insufficient  importance  to  consider 
individually.  (See  Bromin  and  Iodin.)  Hydroflu- 
oric acid  is  the  only  acid  of  fluorin  of  any  importance 
and  this  is  little  used  in  medicine.     (See  Fluorin.) 


72  PHARMACEUTIC    CHEMISTRY. 

DIBASIC  ACIDS 

(Normal  and  Acid  Salts.) 
IlydrosuJjuric  H^S  =  H  —  S  —  H. 
Hydrogen  sultid,  sulfuretted  hydrogen,  prepared 
by  action  of  sulfuric  acid  and  ferrous  sulfid. 
FeS  +  H,SO,  =  FeSO,  +  H^S. 
H— O. 
Hvposiiljiiroiis  Acid,  H2SO2.  /  S. 

H—(V 

Prepared  by  l)urning  sulfur  with  partial  air  supply, 
and  passing  the  gas  into  water.     Thus: 

S,  +  O.,  =  2SO;     2SO  +  2H,0  =  2H2SO,. 
H  —  O. 

Siiljitroiis  And,  H,S(),  =  ^  (S  =  O). 

H  —  ()  ' 

Sulfur   burned   with    oxygen   gives   sulfurous  anhy- 
drid,  SO,,  this  dissolved  in  water  gives. 
SO.,  +  H3O  =  H2SO,. 
Its  salts  are  called  sulfites  and  are  of  some  im- 
portancein  medicine  fur  their  antiseptic  pro])ertiesand 
in  the  arts  as  reducing  agents. 

H  —  O  ,0 

Sii/jiirir  Arid,  H^SO,  =  >S^      . 

H— 0/    ^O 

Oil  of  vitriol.  Hydrogen  sulfate.  Obtained  from 
pvrites,  FeS,  by  heating,  forming  sulfurous  anhydrid, 
oxidizing  and  hydrating  this  to  sulfuric  acid. 

(i)   S,  +  20/=  2SO.,. 

(2)  2HNO,  +  3SO,  =  3SO.,  +  H.O  +  X.,0. 

(3)  SO^  +  H,.0  =  H.,SO,. 


DIBASIC    ACIDS.  73 

Chamber  acid  has  a  specific  gravity  of  1.55. 
Pan  acid  has  a  specific  gravity  of  1.74  =  78%. 
Concentrated  acid  lias  a  specific  gravity  of  1.83  = 

92.5  %• 

It  is  an  oily,  heavy,  corrosive  acid,  colorless  if 
pure,  colored  brown  if  impure.  Dilute  sulfuric  acid 
U.  S.  P.  contains  10%  sulfuric  acid. 

Aromatic  sulfuric  acid  contains  18.5%  absolute  or 
20%  U.  S.  P.  sulfuric  acid,  combined  with  alcohol  and 
aromatic  tinctures. 

Thiflsuljityic  Acid,  HjS.^Og  )(S^ 

-    H—  S^       ^"O. 

Not  found  in  tlie  acid  form,  Init  the  salts  are  used. 

0  —  0 


) 


H  — O.    '^O  — O 

Pvrosidfuric  Acid,  H.S^O,.  ^Sf  | 

H  —  S^    ^0  —  0 
Nord  Hansen  sulfuric  acid,  a  heavy,  browui,  oily 
liquid,  thought  to  be  a  solution  of  SO3  in  HjSO^. 
H— O. 
Carbonic  Acid,  H2CO3.  ^(C  =  O). 

H  — Q/ 

Important  only  for  its  salts,  the  carbonates  and 
bicarbonates.     Unstable,  feeble  acid.     Easily  decom- 
posed, forming  carbon  dioxid,  CO,,  and  water,  HgO. 
H  — O.         .H 
Phosphorous  Acid,  H3PO3.  /^C     • 

H  — O^    ^O 
A  colorless  liquid,  easily  oxidized,  its  salts  are  known 
as  phosphites. 


74  PHARMACEUTIC    CHEMISTRY. 

TRIBASIC  ACIDS. 

(These  Form  Three  Types  of  Salts — Normal, 
Acid  and  Double.) 

H  -  0\ 
Arsenous  Acid,  H.AsOj.     H  —  O— (As). 
H  — O/ 
Prepared  by  roasting  arsenic  ores,  which  produces 
the  arsenous  oxid,  AsOg,  which  is  the  most  impor- 
tant arsenic  compound.     This  oxid,  AsjOg  +  water 
3H2O  =  2H3ASO3.     The  salts  are  known  as  arsenites. 
H  —  0\ 
Arsenic  Acid,  HjAsO,.     H  —  O— ( As  =  O ). 
H  —  ()/ 

Usually  prepared  by  oxidizing  arsenous  acid  by  ni- 
tric acid  and  evaporating  the  solution.  The  salts 
are  known  as  arsenates. 

H  — 0\ 
Orthophosphonc  Acid,  H3PO,.   H  —  O— (P  =  O). 

H  — 0/ 
Phosphoric    acid    ordinary   is    the    most   imjiortant 
acid   of    phosphorus.     Prepared    by   boiling    phos- 
phorus with  dilute  nitric  acid  and  evaporating  to  a 
syrupy  consistency. 

3P2  +  10HNO3  +  4H,0  =  6H3PO,  -f-  5xN,0.,. 
It  is  colorless,  odorless,  strongly  acid  liquid  and  con- 
tains 85%  of  absolute  phosphoric  acid.  Is  mi-cible 
with  water  and  alcohol  in  all  proportions.  It  has  a 
specific  gravity  of  1.7 1  at  15°  C.  Heated  to  200°  C, 
it  loses  water  and  changes  to  pyrophosphoric  acid, 
H2PO7.  At  still  higher  temperatures,  it  forms  meta- 
phosphoric    acid,    HPO,-     Dilute   j)hosphoric    acid 


TRTRABASIC    ACIDS.  75 

U.  S.  P.  contains   lo'y^  of  acid,  and  iias  a  specific 
gravity  of  1.057  '^^  15°  C. 

TETRABASIC  ACIDS. 

(Those  Having  Power  of  Forming  Four  Classes  of 
Salts  or  With  Four  Available  Hydrogens.) 
H  — 0    •P  =  0 


Pyro phosphoric  A cid. 


H  — ()    /P  =  U  \ 
H  — O  \P  =  0  / 


Forms  salts  known  as  pyrophosphates;  sodium  pyro- 
phosphate, Na4P207. 


CHAPTER  IX. 
METALS. 

Over  fifty  metals  are  included  in  the  ordinary 
classification,  but  the  number  is  being  constantly 
increased  by  new  discoveries,  and  older  ones  are  fre- 
cjuently  separated  into  simpler  ones.  Of  these  only 
twenty-seven  are  considered  as  common  metals,  the 
remainder  being  known  as  rare  metals.  This  is  not 
strictly  true,  but  only  those  that  are  of  pharmaceutic 
importance  will  be  considered  in  detail,  and  these 
number  only  about  twenty-five. 

The  classification  and  order  of  study  will  be  lliat 
commonly  employed  in  qualitative  analysis  in  order 
to  teach  both  the  general  properties  and  the  methods 
of  separation  at  the  same  time.  Classifications  in 
relation  to  atomic  weight  and  valence  arc  given  on 
pages  78,  173,  178. 

There  are  certain  characteristic  properties  pos- 
sessed by  all  metals: 

1.  Metallic  luster,  (juite  distinctive. 

2.  (iood  conductors  of  heat  and  electricity,  and 
often  used  for  such  purposes. 

3.  All  solids  at  ordinary  temperature  except  mer- 
cury, which  is  the  only  liquid  metal. 

4.  Nearly  all  electro-positive. 

5.  Color  variable  within  limits  of  shades  of  white 
and  gray,  except  copper  and  gold. 

76 


PROPERTIES    OF    METALS-  77 

6.  Weight,  heavier  than  water,  with  the  exception 
of  lithium,  potassium  and  sodium,  which  are  lighter 
than  water. 

7.  Malleability  marked,  gold  being  exceedingly 
malleable  and  sodium  the  least  so. 

8.  Ductility,  tenacity  or  cohesion,  these  varying 
from  the  greatest  tenacity  of  silver  and  iron  to  lead, 
the  least  tenacious. 

9.  Fusibility,  nonvolatility  at  ordinary  temper- 
ature and  insolubility  in  ordinary  solvents  (water, 
alcohol,  ether). 

The  metals  occur  in  varying  abundance  in  ores, 
rocks  and  soils  throughout  the  earth's  crust  and 
often  as  pure  metal  in  the  so-called  pockets  and  veins. 

The  methods  of  extraction  are  variable  and  will  be 
individually  discussed.  The  following  classification 
will  be  followed  for  the  more  common  metals,  and 
the  rare  metals  will  I)e  discussed  in  a  chapter  by 
themselves. 


78 


PHARMACEUTIC    CHEMISTRY. 


B^U^ 


O        1=1 

i    I    ^- 

g     E     I     o  'a^  ,^ 
S^-'tdZ  o*^  e2;  S--  « 

.    ^    H!    >    ►S" 


g  si  SI  1:1  s^ 


HHe-z^t^H^^- 


•2o  ocn  rtffl  rtS-2-°  ° 


»-;    M     > 


o  O 


E<5  8ooP 


Ib 


2;  '^  o      ^ 


?;  3  0. 

^     S     S  SB    .> 


N 


w 


o  o 


B>: 
E2 


B~ 
2« 

Sir 


^    o 


CHAPTER  X. 
SILVER,  LEAD  AND  MERCURY. 

The  hydrochloric  acid  group,  is  so  called  on  account 
of  their  precipitating  from  their  solutions  by  the  use 
of  hydrochloric  acid  or  soluble  chlorids,  forming 
insoluble  chlorids  with  these  metals. 

This  group  is  also  considered  first  because  of  the 
importance  of  the  compounds  and  the  fact  that  they 
are  fewer  in  number  and  simpler  in  their  composition. 
The  metals  included  are  mercury,  Hg,  which  exists 
in  this  group  in  the  univalent  or  monad  state, 
lead,  Pb,  and  silver,  Ag.  The  salts  or  compounds 
of  the  dvad  mercurv,  will  be  discussed  in  Chapter 
XII. 

MERCURY,  Hg.  Hydrargyrum  U.  S.  P.  At.  Wt., 
198.5  (200).  Sp.  gr.,  13.5.  Valence,  i  and  2. 
Common  name,  quicksilver. 

Source. — Occurs  in  nature  chiefly  as  cinnabar, 
HgS,  mercuric  sulfid;  rarely,  as  globules  of  the  metal 
enclosed  in  rocks.  Obtained  chiefly  from  Spain,  but 
also  in  Peru,  Mexico  and  Japan. 

Preparation. — From  cinnabar  by  roasting,  the 
sulfur  uniting  with  oxygen  to  form  gaseous  sulfur 
dioxid  and  escaping  while  the  mercury  distills. 
Thus,   HgS  +  O,  =  Hg  +  SO3. 

Properties. — A  silver-white,  lustrous   metal,  liquid 
at    ordinary    temperature,    congealing     at     38.8'^ 
79 


8o  PHARMACEUTIC    CHEMISTRY. 

boils  at  360°  and  ver)-  slightly  volatile  at  ordinar)' 
temperature.  It  has  the  same  atomic  weight  and 
vapor  density,  hence  its  molecule  consists  of  one  atom 
only.  If  pure,  it  is  unchanged  at  ordinary  tempera- 
ture, but  above  300°  it  becomes  coated  with  a  film 
of  mercuric  oxid  readily  acted  on  by  nitric  acid  but 
more  difficultly  by  sulfuric  and  hydrochloric  in  the 
cold.  Pure  mercury  poured  on  glass  or  paper  does 
not  adhere  or  form  tails  to  the  drops,  but  retains  its 
spherical  shape.  It  forms  two  series  of  compounds 
the  mercurous  and  mercuric.  The  for  merare  less 
stable,  contain  a  larger  percentage  of  the  metal, 
are  less  soluble  and  consequently  less  poisonous. 

Toxicology. — IMetallic  mercury  is  not  poisonous, 
but  when  it  or  its  salts  become  soluble,  their  poison- 
ous nature  is  very  pronounced.  Children  tolerate 
mercurials  much  better  than  adults.  Treatment  of 
poisoning  should  consist  of  albumen,  as  milk  or  eggs, 
and  prompt  emesis. 

Tests. — Mercurial  compounds  in  solution  arc  read- 
ily detected  by  immersing  a  strip  of  bright  copper 
foil  in  the  solution  in  the  presence  of  free  hydro- 
chloric acid.  A  white-silvery  film  of  copper  amalgam 
quicklv  forms.  Solutions  also  give  a  black  precipi- 
tate with  hydrogen  sulfid  and  a  white  precipitate 
with  hydrochloric  acid  if  in  Ihc  nu-rc  urous  state. 

Uses. — Mercury  nictal  is  used  in  many  amalgams, 
since  it  forms  amalgam.;  with  nearl\  all  metals.  Tin 
amalgam  is  used  for  coating  mirrors.  The  metal  as 
such  is  largely  u.sed  for  thermometers,  barometers, 
thermostats  and  other   instruments,   and  it  enters 


MERCURY.  8 1 

into  five  official  preparations,  viz.:  Emplastrum 
hydrargyri,  U.  S.  P.,  309^ ;  Massa  hydrargyri,  U.  S.  P., 
Zf/c;  Hydrargyrum  cum  creta,  U.  S.  P.,  38%;  Un- 
guentum  hydrargyri,  U.  S.  P.,  50%,  and  Ung. 
hydrargyri  dilutum,  U.  S.  P.,  iz-^c- 

Compounds. — It  may  be  remembered  that  all  the 
official  compounds  of  mercury  are  required  to  be  99^% 
pure,  except  hydrargyrum  ammoniatum,  which  is 
78%.  The  mercurous  salts  of  the  U.  S.  P.  are  but 
two  in  number — for  instance,  the  chlorid,  HgCl, 
and  iodid,  Hgl.  Other  salts  of  some  importance, 
however,  are  the  oxid,  nitrate  and  sulfate. 

I.  Merf«^o«5c///oric?  (Hydrargyri  chor'dum  mile. 
U.  S.  P.),  HgCl,  calomel,  mild  chlorid  of  mercury, 
proto  chlorid,  subchlorid,  submuriate  of  mercury,  or, 
mercurius  dulcis. 

A  heavy,  white,  impalpable  powder,  insoluble, 
volatile,  prepared  usually  by  subliming  mercury, 
mercury  sulfate  and  sodium  chlorid,  and  washing  out 
the  corrosive  chlorid  that  also  forms. 

Hg  +  HgSO,  +  2NaCl  =  2HgCl  +  Na^SO,. 
It  may  be  also  prepared  by  heating  mercury  with 
mercuric  chlorid:  Hg  +  HgCU  =  2HgCl;  by  mixing 
solutions  of  mercurous  nitrate  and  sodium  chlorid: 
Hg  (NO3)  +  NaCl  =  NaNOg  +  HgCl;  also  by  a 
solution  of  mercurous  nitrate  and  mercuric  chlorid, 
Hg.CNO,)^  +  HgCl3  =  2HgCl  +  Hg  (NOg)^.  It  is 
used  medicinally  as  a  laxative  and  alterative. 

Yellow    mercurous   iodid    (Hydrargyri    iodidum 
tlavum  U.  S.  P.),  Hgl,  protoiodid,  yellow  iodid,  green 
iodid,  hydrargyri  iodidum,  viride,  U.  S.  P.,  '80.     A 
6 


82  PHARMACEUTIC    CHEMISTRY. 

yellowish-green,  insoluble  salt  prepared  by  dissolv- 
ing mercury  in  dilute  nitric  acid  to  form  mercurous 
nitrate  and  decomposing  this  with  potassium  iodid: 
(i)  Hg2  +  2HNO3  =  2HgN03  +  H2 
(2)  HgNOg  -f  KI  =  Hgl-f  KNO,. 
Used  as  an  alterative. 

Mercurous  oxid,  HgjO,  protoxid,  or  black  oxid, 
prepared  by  interaction  of  sodium  hydrate  and  mer- 
curous nitrate.  Hg2(N03)2  +  aNaOH  =  HgjO  -f- 
2NaN03  +  HjO.  A  brownish-black,  heavy,  taste- 
less, insoluble  powder;  unstable,  sunlight  converting 
it  into  mercuric  oxid  and  mercury.  It  is  the  essential 
ingredient  of  lotio  nigra,  or  black  wash  of  the  N.  F., 
made  by  adding  calomel  to  lime-water,  2HgCl  -|- 
Ca(t)H)2  =  Hg^O  -f  CaClj  +  H^O. 

Mercurous  nitrate,  HgNOg,  white  or  colorless, 
prismatic  and  very  unstable,  efflorescent,  crystals 
prepared  by  action  of  dilute  nitric  acid  on  mercury. 
6Hg  +  8HNO3  =  sUg,  (NO,),  +  N2O2  +  4H26. 
Mercurous  sulfate,  HgjSO^,  a  white,  crystalline  salt, 
easily  decomposed  to  the  basic  salt,  prepared  by 
action  of  sulfuric  acid  on  an  excess  of  mercury,  is 
of  very  little  value.  For  discussion  of  mercuric  com- 
j)ounds,  see  Chapter  XII. 

LEAD,  Plumbum,  Pb,  205.  Sp.  gr.,  11.4.  Melt- 
ing point,  325°.  Sometimes  found  free,  but  com- 
mercially in  abundant  ores  chiefly  as  sulfid,  galena, 
PbS,  and  as  carbonate,  cerusite,  PbCOg.  The  ores 
usually  contain  some  silver,  which  is  removed  by 
crystallizing  and  cupelling.  The  lead  is  obtained  by 
continued  roasting  of  the  ores. 


LEAD.  83 

Properties. — A  soft  metal,  bluish-white,  brilliant 
silvery  luster  on  fresh  surfaces,  but  quickly  tarnished. 
It  is  malleable  and  pliable,  but  not  ductile  or  tena- 
cious. Conducts  heat  well,  electricity  poorly,  melts 
at  325°  and  volatilizes  at  a  white  heat.  It  is  pre- 
cipitated from  its  solutions  by  zinc,  tin  and  iron, 
acted  upon  slowly  by  most  acids,  but  freely  by  nitric 
acid.  In  presence  of  air,  water  dissolves  lead  by 
forming  the  hydroxid.  Nitrates  and  nitrites  in- 
crease, and  carbonates,  chlorids  and  sulfates  decrease 
this  solubility.  These  facts  are  important  because 
potable  waters  are  so  commonly  conducted  through 
lead  pipes. 

Uses. — The  commercial  uses  of  the  metal  are  well 
known.  It  also  forms  a  number  of  useful  alloys: 
with  tin  it  forms  solder,  fusible  at  186°;  with  zinc  it 
forms  Babbitt  metal,  and  with  antimony  forms  type- 
metal  and  is  an  ingredient  of  types  of  glass  known 
as  flint  glass.  The  greatest  consumption  of  lead, 
outside  of  its  mechanical  uses  in  pipes,  sheetings,  etc., 
is  probably  as  a  paint  pigment  in  the  form  of  basic 
lead  carbonate,  or  white  lead,  2PbC03  PbCOH)^, 
even  yet  largely  manufactured  by  the  old  Dutch 
method,  dependent  upon  the  corrosion  of  the  lead 
by  acetic  acid  in  the  presence  of  carbon  dioxid  and 
moist  air.  Other  methods  have  been  devised, 
but  the  Dutch  method  seems  to  give  the  greatest 
satisfaction. 

Toxicology. — All  soluble  lead  compounds  and  those 
that  are  rendered  soluble  in  digestive  fluids  or  other- 
wise in  the  animal  economy  are  quite  poisonous. 


84  PHARMACEUTIC    CHEMISTRY. 

The  chronic  form  of  poisoning,  known  as  painters' 
colic,  is  very  common,  due  to  contact  with  the  com- 
pounds of  lead  in  painting,  etc. 

The  acute  conditions  of  poisoning  are  quite  rare 
and  seldom  fatal  and  usually  produced  by  a  large 
single  dose  of  such  salts  as  acetate  or  carbonate. 
When  such  a  case  occurs,  magnesium  sulfate  should 
be  at  once  administered,  as  it  produces  an  insoluble 
sulfate  with  the  lead.     Emesis  should  be  induced. 

Compounds. — lead  acetate,  (PlumbiacetasU.S.P.), 
Pb  (€211302)2  +  3H,0.  sugar  of  lead,  sal  saturni, 
colorless,  shining,  transparent,  prisms  or  plates, 
heavy  crystalline  masses  or  granules,  with  a  faint 
acetous  odor,  sweetish,  astringent,  metallic  taste; 
efflorescent;  absorbs  carbon  dioxid  from  the  air. 
Soluble  in  two  parts  of  water.  Incompatible  with 
very  many  substances,  such  as  alkali  salts,  organic 
salts  and  soluble  chlorids  and  sulfates.  May  be 
made  by  dissolving  lead  oxid  in  acetic  acid  and  crys- 
tallizing. PbO  +  2C,H,02  =  Pb(C2H302)2  +  H2O. 
Used  medicinally  as  an  external  astringent.  Enters 
into  emplastrum  plumbi,  ung.  diachylon,  50*7^;  liq. 
plumbi  subacetate,  25%;  liq.  plumbi  subacetatis 
dilutus,  1%,  and  ceratum  plumbi  subacetatis — 20%. 
Lead  iodid,  Plumli  iodidum,  Pbl,,  precipitated 
from  lead  solutions  by  potassium  iodid.  Should  be 
preserved  in  well-stoppered  bottles  away  from  light. 
A  heavy,  bright-yellow  powder,  odorless,  tasteless 
and  slightly  soluble  in  water.  (1-1300)  99%  pure. 
Used  medicinally  as  a  sorbefacient.  The  ointment 
of  lead  iodid,  ro'',',  was  formerly  official. 


SllA'KK.  85 

Lead  nitrate  (Plumbi  nitras),  Pb(N03)2,  99.5% 
pure.  Prepared  by  dissolving  lead  or  its  oxids  in 
excess  of  nitric  acid.  PbO  +  2HNO3  =  Pb(N03)2 
+  H2O.  Colorless,  octahedral  crystals,  sometimes 
transparent,  often  nearly  opaque.  Odorless,  sweet- 
ish, astringent,  metallic  taste.  Soluble  in  less  than 
two  parts  of  water.  It  is  used  as  a  caustic  applied 
as  a  powder;  its  solution  is  used  as  a  disinfectant. 

Lead  oxld  (Plumbi  oxidum),  PbO,  96%  pure, 
(litharge).  Prepared  by  heating  metallic  lead,  its 
carbonate  or  nitrate  with  access  of  air,  obtained 
largely  as  a  by-product  in  silver  extraction.  A  heavy, 
yellow  or  reddish -yellow  powder,  odorless  and  taste- 
less. Insoluble  in  ordinary  solvents,  readily  so  in 
acetic  and  nitric  acids.  Used  in  the  preparation  of 
various  lead  salts,  solution  of  lead  subacetate  and 
formerly  in  preparing  lead  plaster.  Other  oxids 
of  lead:  dioxid,  PbOj,  plumboso-plumbic  oxid,  or 
red  lead,  PbgO^,  and  plumbic  suboxid,  PbjO.  None 
are  of  much  importance.  Lead  chromate,  PbCrO^, 
"chrome  yellow,"  is  much  used  as  a  pigment.  Lead 
sulfid  and  lead  carbonate  have  been  mentioned. 

SILVER,  Ag.,  Argenium,  108.   Valence,  i. 

Occurrence. — Occurs  native  to  a  small  extent, 
but  principally  as  ores  in  combination  with  chlorin, 
bromin,  sulfur,  etc.  Associated  with  lead,  copper, 
gold,  etc.  Found  principally  in  western  United 
States,  Mexico,  Hungary  and  Saxony. 

Preparation. — The  ore  is  roasted  with  sodium 
chlorid  forming  silver  chlorid,  and  this  is  decom- 
posed by  iron  scraps.     Metallic  mercury  is  added. 


86  PHARMACEUTIC    CHEMISTRY. 

forms  an  amalgam  with  the  silver,  and  the  mercury  is 
distilled  from  it.  Different  ores  require  individual 
treatment,  however,  and  works  on  metallurgy  should 
be  consulted  for  full  details  of  extraction. 

Properties. — It  is  a  white,  lustrous  metal,  perma- 
nent in  the  air,  very  malleable,  tenacious,  and  ductile. 
An  excellent  conductor  of  heat  and  electricity,  feebly 
attacked  by  most  acids,  but  freely  by  nitric  acid. 
Specific  gravity,  10.5;  melting-point,  1040°. 

Uses. — Seldom  used  by  itself,  on  account  of  its 
softness,  but  usually  combined  with  copper  to  harden 
it.  Used  much  in  art  work,  cutlery  and  as  a  coin 
medium,  ornaments,  etc.  Coin  silver  contains  10% 
copper  in  the  coins  of  the  United  States,  France, 
Germany  and  Austria.  British  coin  silver  contains 
7.5%  copper.  In  pharmacy  and  medicine  silver  is 
used  for  surgical  instrument  ])lating  and  in  the 
preparation  of  silver  salts. 

Compounds. — Silver  cyanid  (Argenti  cyanidum 
U.  S.  P.),  AgCn;  purity,  99.5%,  equivalent  to  80.5% 
metallic  silver.  Prepared  by  passing  hydrocyanic 
acid  through  solution  of  silver  nitrate  or  adding  a 
soluble  cyanid  to  the  same. 

Properties. — A  white,  permanent  powder,  odorless 
and  tasteless.  Insoluble  in  ordinary  solvents,  but 
soluble  in  ammonia  water  and  potassium  cyanid 
solution.  In  solution  with  the  latter  it  is  used  in 
electro-plating.  Used  for  the  extemporaneous  prep- 
aration of  dilute  hydrocyanic  acid,  2% 

Silver  nitrate  (Argenti  nitras  U.  S.  P.),  AgNOj) 
purity,  99.9%.     Should  be  kept  protected  from  light. 


SILVER    SALTS.  87 

Preparation. — Made  by  dissolving  silver  in  diluted 
nitric  acid. 

Properties. — Colorless,  transparent,  tabular  rhom- 
bic crystals  reduced  to  grayish-black  by  light  or 
organic  matter.  Odorless  with  a  strongly  metallic 
and  caustic  taste.  Soluble  in  0.54  parts  of  water, 
24  parts  of  alcohol.  Incompatible  with  alkalies, 
most  acids  and  organic  matter.  Melts  at  about 
200°  to  a  faintly  yellow  liquid.  When  so  fused  and 
cooled  in  moulds,  it  forms  the  oflticial  argenti  nitras 
fusus  U.S.  P.,  known  as  lunar  caustic  and  "lapis  in- 
fernalis."  When  one  part  silver  nitrate  and  two 
parts  potassium  nitrate  are  fused  together  and 
moulded,  it  is  called  argenti  nitras  dilutus  U.  S. P., 
or  mitigated  caustic.  The  salt  is  useful  as  an  anti- 
septic, astringent  and  caustic.  It  also  finds  use  in 
photography,  in  the  manufacture  of  hair  dyes,  indeli- 
ble inks  and  in  silvering  mirrors,  etc.  It  is  poisonous, 
sodium  chlorid  being  the  best  antidote.  Silver 
stains  on  the  skin  may  be  removed  by  solution  of 
potassium  cyanid,  sodium  thiosulfate  or  ammonia 
water. 

Silver  oxid  (Argenti  oxidum),  AgjO;  purity, 
99.8%;  equivalent  to  92.9%  silver.  Easily  reduced 
by  light  organic  matter  and  ammonia. 

Properties. — A  heavy,  dark-brownish  to  black 
powder,  odorless,  with  metallic  taste.  Slightly 
soluble  in  water.  Decomposed  at  300°.  Feebly 
astringent. 

The  chlorid,  bromid  and  iodid  of  silver  are  very 
similar,    insoluble,    easily    reduced   and    find    their 


88  I'llAKMACELTIC    CHEMISTRY 

greatest  use  in  photography,  which  depends  upon 
the  ready  reduction  of  these  salts  when  exposed  to 
light. 

Toxicology. — Poisoning  by  silver  salts  is  quite  rare, 
sodium  chlorid  or  other  soluble  chlorids  being  the 
antidotes. 


CHAPTER  XL 
ARSENIC,  ANTIMONY,  TIN. 

This  group  is,  as  a  whole,  known  as  the  hydrogen 
sulfid  group,  because  the  metals  included  in  the 
group  will  be  precipitated  from  acid  solution  by  the 
general  group  reagent,  hydrogen  sulfid,  HjS.  After 
separating  the  metals  of  Group  I  by  hydrochloric 
acid,  the  residual  solution  is  treated  with  a  current 
of  hydrogen  sulfid  gas.  The  metals  are  precipitated 
as  sulfids.  We  further  divide  this  group  into  two 
divisions.  Those  metallic  sulfids 'previously  formed 
that  are  soluble  in  ammonium  sulfid,  viz.:  arsenic, 
antimony  and  tin;  and  those  insoluble  in  ammonium 
sulfid,  viz.:  bismuth,  copper,  cadmium,  mercuric 
mercury  and  lead.  Tlie  former  group  is  the  sub- 
ject of  this  chapter.  The  medicinal  uses  of  these 
metals  are  but  few  and  very  few  of  the  salts  are  offi- 
cial. Arsenic  is  the  most  valuable  of  the  three, 
medicinally. 

ARS2NIC,  Arsenum,  As,  74.4.  Mol.  wt.,  299. 
Sp.  gr.,  5.7.  Arsenic  is  found  free  in  nature, 
but  usually  combined  with  sulfur  or  oxygen.  Its 
principal  ores  are  orpiment,  AsjSg,  realgar,  AS2S2,  and 
iron  arseno-sulfid,  FeAsS,  also  called  "  mispickel "  or 
arsenical  pyrites.  It  is  widely  scattered,  though  in 
minute  quantities,  throughout  inorganic  and  many 
organic    compounds.     It    is    commonly    present    in 


90  PHARMACEUTIC    CHEMISTRY. 

iron  jnrites  and  through  this  channel  finds  its  way 
as  an  impurity  into  sulfuric  acid,  which  is  ])rc])ared 
from  pyrites. 

Preparation. — Arsenic  is  prepared  from  pyrites 
by  roasting  to  volatilize  the  arsenic  which  afterwards 
is  purified  by  distillation. 

Properties. — Arsenic  in  many  ways  resembles  a 
true  metal,  but  it  also  has  the  properties  of  a  non- 
metal,  and  since  it  possesses  both  the  properties,  it  is 
often  styled  a  metalloid  (metal-like)  element.  It  oc- 
curs both  as  amorphous  substance  and  in  irregular 
rhombohedral  crystals.  It  volatilizes  above  ioo°  C. 
and  at  i8o°  C.  is  vaporized  rapidly  without  melting. 
When  so  heated  in  presence  of  air,  it  unites  with 
oxygen,  producing  grayish  fumes  which  possess  a 
garlicky  odor.  It  burns  with  a  bluish  flame,  which 
results  in  the  production  of  an  oxid.  This  oxid, 
chemically  a  trioxid,  has  the  formula  of  AsjOj. 
Arsenic  finds  uses  in  the  "hardening  of  shot,  in 
pyrotechny,  in  the  manufacture  of  paint  pigments 
and  is  alloyed  with  iron  and  copper  to  increase  their 
degree  of  brilliancy  when  polished.  It  is  also  used 
to  produce  many  of  the  vermin  poisons  in  agriculture. 

Compounds. — Arsenic  forms  two  classes  of  com- 
pounds, the  "ic"  and  the  "ous."  In  the  "ous" 
condition,  it  acts  as  a  trivalent.  In  the  "ic"  as  a 
pentavalent.  Arsenic  oxid,  As-^Oj,  when  dissolved 
in  water  forms  arsenic  acid,  which  has  the  formula 
H3ASO4,  and  which  forms  salts  called  arsenates. 
The  arsenic  oxid  is  less  poisonous  than  the  arsenous 
oxid.     This  latter  oxid,  ofiicial  in  the  U.  S.  P.  under 


ARSENIC.  91 

the  title  of  arseni-trioxidum,  AsjOg,  commonly  called 
arsenic,  white  arsenic,  arsenic  trioxid  or  ratsbane,  is 
a  white,  gritty,  crystalline  powder,  which,  fused  in 
sealed  glass  tubes,  produces  a  vitreous  mass  grad- 
ually becoming  opaque.  It  is  slightly  soluble  in 
water,  producing  arsenous  acid,  HjAsOg,  which 
forms  unstable  salts  known  as  arsenites.  The 
official  article  should  be  not  less  than  99.8%  pure. 
The  glassy  variety  changes  by  exposure  to  moist 
air  to  the  opacjue  variety  which  is  more  readily  soluble. 
Medicinally,  arsenic  is  used  as  a  caustic,  tonic  and 
alterative,  thought  to  be  specific  in  various  skin  dis- 
eases. It  enters  into  the  solution  of  arsenous  acid 
(liquor  acidi  arsenosi,  1%),  the  Donovan  solution 
(liquor  arseni  et  hydrargyri  iodidi,  1%  each),  into  the 
solution  of  sodium  arsenate  (liquor  sodii  arsenatis, 
1%),  and  into  the  Fowler's  solution  (liquor  potassii 
arsenitis,  1%).  Of  the  chemical  compounds  of 
arsenic  official  we  find  the  iodid  (arseni  iodidum), 
Aslg,  which  represents  16.3%  of  metallic  arsenic  and 
82.7%  of  iodin.  It  is  made  by  the  direct  union  of  the 
elements.  It  occurs  in  orange-red,  crystalline  odor- 
less powder,  soluble,  but  partly  decomposed  in  12 
parts  of  water,  readily  soluble  in  ether  and  chloro- 
form. It  should  be  protected  from  heat  and  light.. 
The  iodid  is  incompatible  with  most  metallic  salts, 
except  the  alkali  metals.  It  is  easily  reduced  or 
oxidized.  Medicinally,  the  salt  is  used  as  an  altera- 
tive. Arsenic  forms  similar  compounds  with  the 
other  halogen  elements.  Three  sulfids  of  arsenic 
are    known:    arsenous    sulfid,    AsjS,,    the    disulfid. 


92  PHARMACEl'TIC    CHEMISTRY. 

AS2S2,  and  the  pentasulfid,  AsjSj.  Cupric  arsenite 
Cu3(As()3)2,  is  called  Scheele's  green.  Paris  green, 
or  Schweinfurt's  green,  is  a  variable  mi.xture  of 
copper,  acetate  and  arsenite,  usually  supposed  to 
be  cupric  aceto-arsenite,  made  by  boiling  arsenous 
oxid  in  a  solution  of  copper  acetate  and  the  formula 
Cu(C2H302)2, 3Cu(As02)2)  has  been  ascribed  to  it. 
Both  the  greens  are  used  as  pigments  in  wall  paper 
printing  and  the  detached  particles  therefrom  have 
frequently  produced  symptoms  of  chronic  arsenical 
poisoning.  The  detection  of  arsenic  in  wall  paper  is 
frequently  called  for  and  the  pharmacists  should  be 
ready  to  perform  the  same. 

Toxicology. — Arsenic  is  an  important  poison  and 
from  the  time  of  its  discovery  has  been  used  for  crimi- 
nal purposes.  All  soluble  compounds  of  arsenic  are 
poisonous,  the  poison  usually  enters  the  system  by 
the  mouth,  but  it  may  be  absorbed  by  the  skin,  mem- 
branes or  by  breathing.  It  permeates  the  entire 
body,  but  deposits  more  specifically  in  the  liver. 
It  is  excreted  both  by  the  feces  and  by  urine.  In 
case  of  poisoning  with  arsenic,  the  stomach-tube  is 
the  first  indication,  emetics  should  be  ])romptly 
administered.  The  chemical  antidote  is  the  ferric 
hydroxid  or  better  the  official  ferric  hydroxid  with 
magnesia  (ferri  hydroxidum  cum  magnesii  oxido), 
commonly  known  as  the  "arsenic  antidote."  This 
antidote  is  most  admirable  in  its  action:  thus,  the 
magnesium  oxid  which  it  contains  neutralizes  the 
acid  of  the  gastric  contents,  producing  neutral  salt 
and  thus  preventing  the  solution  of  arsenic  therein. 


MARSH    TEST.  93 

Dialysed  iron  is  another  form  of  iron  found  very 
effective,  in  both  cases  the  iron  combining  with  the 
arsenic  and  forming  an  insoluble  ferric  arsenate. 

Tests. — Numerous  tests  for  the  detection  of  arsenic 
are  available,  but  no  single  test  should  be  regarded  as 
conclusive.  Marsh's  test  is  possibly  the  most  im- 
portant, though  in  presence  of  organic  matter  it  is  not 
positive.  This  is  conducted  as  follows:  introduce 
into  a  flask  some  arsenic-free  zinc  (U.  S.  P.  reagent) 
cover  it  with  dilute  sulfuric  acid,  close  the  flask  with 
a  stopper,  perforated  and  supplied  with  a  safety 
tube  and  provided  with  another  tube  turned  at 
right  angles  horizontally  drawn  out  to  a  fine  point. 
The  metallic  zinc  decomposes  the  acid  and  generates 
hydrogen,  which  in  turn  should  be  allowed  at  least 
fifteen  minutes  to  drive  out  all  the  air  from  the  con- 
tainer. The  arsenical  solution  should  next  be  in- 
troduced through  the  safety  tube,  the  gas  at  the  open 
end  of  the  tube  should  next  be  lighted  and  a  piece 
of  cold  porcelain  dish  (a  porcelain  crucible  lid  will 
do)  held  against  the  flame;  if  no  black  stain  appears, 
arsenic  and  anti  mony  are  not  present.  If  a  brownish- 
black  spot  is  deposited,  which  when  treated  with  a  few 
drops  of  a  solution  of  a  hypochlorite  dissolves,  it 
indicates  arsenic.  If  it  does  not  dissolve,  antimony 
is  indicated.  This  test  depends  on  the  formation 
of  arsin  gas,  ASH3,  the  product  of  the  action  of  nas- 
cent hydrogen  on  arsenic  in  acid  solutions. 

Fleitmann's  test  depends  on  dropping  a  few  pieces 
of  metallic  zinc  or  aluminum  in  a  solution  of  potas- 
sium hvdroxid,  which  contains  a  small  quantity  of 


94  I'liARMAciamc  chemistry. 

the  arsenical  solution.  The  test-tube  is  covered  with 
a  piece  of  filter  paper  which  has  previously  been  moist- 
ened with  a  solution  of  AgNOg.  The  arsin  gas  which 
is  evolved  acts  upon  the  silver  nitrate  reducing  it  to 
metallic  silver  which  produces  a  dark  stain  upon  the 
paper.  This  test  is  important  and  valuable  in  that 
it  differentiates  arsenic  from  antimony  (stibin  not 
being  evolved). 

Guttzeit^s  test  depends  upon  the  reduction  of  lei  d 
acetate  by  arsin,  and  Reinsch's  test  depends  upon 
the  reducing  powers  of  copper  on  arsenical  com- 
pounds. 

ANTIMONY,  Stibium,  Sb,  119.3.  Sp.  gr.,  6.7. 
Melting-point,  450  C. 

Occurrence. — Antimony  occurs  native,  scattered 
widely,  but  only  in  minute  particles.  It  is  found  in 
combination  as  an  oxid,  SbjOg,  commonly  known  as 
"antimony  bloom"  or  white  antimony,  and  as 
antimony  ochre,  AsSb^O^.  In  combination  with 
sulfur,  it  occurs  as  stibnite,  SbjSg,  which  is  its  most 
important  ore  and  commercial  source.  It  is  also 
found  combined  with  iron,  copper,  lead  and  other 
sulfids. 

Preparation. — Antinn)ny  is  obtained  from  the 
sulfids  by  heating  with  scrap  iron  in  carbon  crucibles 
or  by  roasting  the  ore  with  half  its  weight  of  charcoal. 
The  two  methods  of  extracting  the  metal  from  the 
ores  will  best  be  seen  by  the  following  two  equations: 

(i)  Sb^Sg  +  3Fe  =  Sb2  +  3FeS. 

(2)  SbjO,  +  2C2  =  4CO  +  Sb... 

Properties. — Antimony   is    a    bright,    silver  white, 


ANTIMONY    COMPOUNDS.  95 

br'ttle  metal  of  crystalline  structure,  permanent 
at  ordinary  temperature,  but  at  high  heat  it  burns 
with  a  brilliant  flame  forming  the  trioxid,  Sb-^Og. 
In  cooling  after  liquefaction  it  expands,  and  this 
property  makes  it  very  valuable  as  an  alloy.  Its 
principal  alloys  are:  type-metal  (antimony,  lead 
and  tin)  and  britannia  metal  (antimony,  copper  and 
tin).  Antimony  is  a  poor  conductor  of  heat  and 
electricity.  When  acted  upon  by  concentrated  sul- 
furic or  hydrochloric  acid,  it  forms  salts;  by  nitric 
acid,  it  is  oxidized,  forming  oxids. 

Compounds. — Antimony  forms  both  "ic"  and 
"ous"  compounds,  nearly  all  of  which  are  decom- 
posed by  water.  Tartar  emetic  (antimonii  et  potas- 
sii-  tartras)  is  the  only  ofl&cial  salt  of  antimony. 
It  has  the  formula  2K(SbO)C,H,06  +  H2O  and 
is  prepared  by  boiling  antimonous  oxid,  SbjOg, 
with  potassium  bitartrate,  filtering  and  evaporating 
the  solution.  Reaction:  SbaOg  +  2KHC4H^Og  = 
2K(SbO)C4H40e-|-H20.  Potassium  antimonyl  tar- 
trate (its  chemical  name)  is  a  white  crystalline  salt, 
soluble  in  hot  water,  slowly  in  cold  water;  used  as 
an  emetic  and  expectorant,  it  enters  into  the  com- 
pound syrup  of  squills  (syrupus  scillae  compositus, 
0.4%).  Antimony  forms  salts  much  the  same  as 
described  under  arsenic:  Stibin,  SbHg;  several  halo- 
gen salts,  among  which  the  trichlorid,  SbClg, 
commonly  know^n  as  "butter  of  antimony,"  finds 
much  use  in  the  arts  and  manufactures.  It  forms 
three  oxids,  Sb,©,,  Sb204  and  SboOj.  It  also 
forms  two  sultids,  Sb20^  and  ^h^^^^,  and  a  number 


96  PIJARMACKUTIC    CHEMISTRY. 

of  less  important  salts.  In  the  U.  S.  P.  (8th  Rev.) 
antimony  sulfid,  purified  antimony  sulfid,  antimony 
oxid,  all  of  use  in  the  preparation  of  other  antimony 
compounds,  but  rarely  used  alone,  have  been  dis- 
missed. The  tests  described  under  arsenic,  especially 
Marsh's  and  Fleitmann's  test,  of  which  the  latter  is 
valuable  in  that  it  differentiates  the  antimony  from 
the  arsenic,  are  valuable. 

TIN. — Slannum,  Sn,  117.     Sp.  gr.,  7.3. 

Occurrence. — Tin  does  not  occur  native,  but  al- 
most entirely  as  oxid.  Tin-stone,  SbOj,  commonly 
known  as  cassiterite,  is  its  principal  ore.  When 
found  in  veins  of  rock,  it  is  called  mine-tin  and  when 
occurring  in  water  beds,  it  is  known  as  stream  tin. 
It  is  sometimes  found  associated  with  other  metals 
as  a  sulfid.  Its  principal  mines  are  in  Cornwall  and 
England.  In  America  it  is  found  in  California, 
South  Dakota  and  New  Hampshire. 

Preparalio)!. — The  jjroccss  of  extracting  tin  from 
its  ores  ordinarily  consists  in  three  steps:  (1)  calcin- 
ing; (2)  washing;  (3)  reducing  or  smelting.  The 
impure  metal  is  cast  into  ingots  which,  when  sub- 
jected to  regulated  heat,  allow  the  tin  to  melt  and 
run  off,  leaving  behind  the  iron  and  copper. 

Properties. — A  .soft,  white  metal,  harder  than  lead, 
not  acted  upon  bv  water  or  air  at  ordinary  tempera- 
tures. Malleable,  forming  tin-foil,  and,  at  tempera- 
tures just  below  melting,  brittle.  At  high  tempera- 
tures it  burns,  forming  an  oxid.  It  alloys  with 
other  metals,  forming  many  useful  ones,  such  as 
l)ewter,  solder,  l)rasses,  ])ronzes,  britannia  and  type- 


TIN.  97 

metals,  fusible  alloys  with  l)ismuth,  etc.  It  is  used 
as  a  protective  of  iron  and  other  metals,  by  covering 
them  with  a  thin  layer  of  tin.  Tinware  usually 
is  made  of  sheet  iron  covered  with  tin.  Its  salts 
are  used  as  mordants  in  dyeing  and  cloth  printing. 
It  forms  two  classes  of  compounds,  the  "ous"  and 
the  "ic,"  the  first  being  divalent,  the  second  tet- 
ravalent.  It  forms  oxids — stannous  oxid  (SnO) 
and  stannic  oxid  (SnOj) — the  former  black  and 
the  latter  white.  These  oxids  form  two  acids  with 
water — stannic  acid  (H2Sn02),  and  metastannic 
acid  (Hi(,SngO,g).  The  latter  is  also  produced  by 
acting  with  concentrated  nitric  acid  on  metallic  tin. 
No  salts  of  tin  are  official,  and  find  no  application  in 
medicine.  The  salts  are  poisonous,  but  rarely  used 
as  poisons.  Accidental  cases  of  poisoning  do  occur 
in  dye  works,  etc.,  in  which  cases  emetics  and  demul- 
cent drinks,  like  milk,  should  be  administered  freely. 
Tests. — Tin  may  be  detected  by  precipitating  it 
from  solution  by  hydrogen  sulfid,  converting  it  into 
oxid  with  nitric  acid  and  weighing  as  such,  if  the 
quantity  is  desired. 


CHAPTER   XII. 
HYDROGEN  SULFID  GROUP  (Second  Division). 

BISMUTH,  COPPER,  CADMIUM  AND  MERCURY 

("IC"). 

This  is  somewhat  similar  to  the  group  just  de- 
scribed. The  metals  to  be  discussed  are  precipi- 
tated by  hydrogen  sulfid,  but  members  of  this  group 
are  insoluble  in  ammonium  sulfid  solution,  hence 
they  are  grouped  together. 

BISMUTH.— Bismulhum,  Bi,  207.  Sp.  gr.,  9.9. 
Bismuth  differs  from  the  other  metals  previously  con- 
sidered in  that  it  occurs  most  commonly  in  the  un- 
combined  state.  However,  it  is  also  found  as  an 
oxid  (BijOg),  as  bismuth  ochre,  and  as  sulfid  (Bi._,S.,) 
in  bismuth  glance.  Its  principal  minesare  in  Saxony, 
where  the  metal  is  found  associated  with  silver,  co- 
balt and  nickel. 

Preparation. — The  ores  are  heated  in  inclined  iron 
pipes,  and  the  melted  bismuth  run  off  from  the  other 
material.     Subsecjuent  purification  is  necessary. 

Properties. — It  is  a  white,  lustrous  metal  with  a 
reddish  tint,  very  brittle,  fusible  at  268^  Centigrade, 
volatile  at  higher  temperatures,  and  at  very  high 
heat  it  burns,  forming  the  trioxiil  Bi.O.,.  it  is 
unaft'ected  by  dry  air  at  ordinary  tcmi)crature,  t)Ut  is 
tarnished  in  moist  air.  It  is  attacked  only  slightly 
98 


BISMUTH    COMPOUNDS.  99 

by  hydrochloric  acid,  but  more  readily  by  sulfuric 
and  nitric  acids.  It  is  a  poor  conductor  of  electricity 
and  it  expands  on  cooling  after  fusion.  If  slowly 
cooled,  obtuse  rhombohedral  crystals  may  be  ob- 
tained. 

The  metal  is  but  little  used  except  in  alloys,  to 
which  it  imparts  ease  of  fusion  and  at  the  same  time 
hardness.  It  plays  the  part  of  both  a  metal  and  a 
nonmetal  under  differing  conditions.  Its  com- 
pounds are  much  used  in  medicine.  It  forms  both 
"ous"  and  "ic"  compounds,  having  the  valence  of 
3  and  4,  respectively.  Most  neutral  salts  of  bis- 
muth are  converted  into  basic  salts  by  water,  and 
these  latter  are  mostly  used  in  medicine. 

Bismuth  Citrate  (Bismuthi  Ci  ras  U.S.  P.)  — 
BiCgHsO^,  should  contain  not  less  than  58%  nor 
more  than  60%  of  pure  bismuth  oxid.  It  is  pre- 
pared by  the  action  of  the  subnitrate  on  a  solution 
of  citric  acid:  (BiONOs  -f  HjO)  +  {Yl^C^Yi^O^  + 
H2O)  =  BiCgHjO^  +  HNO3  +  3H2O.  It  is  a 
white,  amorphous  or  crystalline  powder,  odorless, 
tasteless,  insoluble  in  water,  but  soluble  in  ammonia 
water.  It  is  used  as  the  base  of  soluble  bismuth 
and  ammonium  citrate — bismuthi  et  ammonii  citras 
U.  S.  P.     It  is  astringent  and  antiseptic. 

Bismuth  and  Ammonium  Citrate  (Bismuthi  et 
Ammonii  Citras  U.  S.  P.) — Similar  in  uses  to  the 
citrate.  It  is  a  scale  salt  prepared  by  dissolving 
the  citrate  in  dilute  ammonia  water  and  subsequent 
scaling. 

Bismuth    Subcarbonate    (Bismuthi  Subcarbonas 


lOO  I'llARMACEUTIC    CHEMISTRY. 

U.S. P.) — Comp().'^ition  is  variable.  Purity,  90^^.  It 
is  a  white  or  pale  yellow,  odorless,  tasteless  and 
insoluble  powder,  decomposed  by  mineral  acids. 
It  is  prepared  from  the  su!)nitrate  and  an  alkali 
carbonate: 

2Bi(N03)3  +  sNa^COj  +  H,0  =  (BiO).,C03  + 
H2O  +  6NaN03  +  2CO2. 

Bismuth  Subgalate  (Bismuthi  Subga'asU.S.P.) — 
Has  a  variable  composition.  It  should  contain  from 
52%  to  57%  bismuth  oxid.  It  is  an  amorphous, 
bright-yellow,  odorless,  tasteless,  insoluble  powder, 
decomposed  by  strong  acids.  It  may  be  prepared 
l)y  mixing  a  warm  solution  of  gallic  acid  with  bis- 
muth nitrate  and  glacial  acetic  acid;  the  substance  is 
also  designated  "dermatol." 

Bismuth  Subnitrate  (Bismuthi  Subnitras  U.S. P.) 
— BiONC).,.  .Also  called  "magisterium  "  and  basic 
bismuth  nitrate.  It  should  yield  So^^p  of  bismuth 
oxid,  and  is  of  varying  composition.  Description: 
It  is  a  white,  odorless,  insoluble,  almost  tasteless 
powder,  soluble  in  mineral  acids,  incom])atible  with 
alkaline  carbonates,  iodids,  chlorids,  tannatcs,  etc. 
It  is  prepared  by  dissolving  the  metal  in  nitric 
acid  and  pouring  the  nitrate  into  a  large  (|uantity 
of  water,  whereby  the  sul)nitrate  is  ])re(ipilated. 
Thus: 

(i)  2Bi  +  8HNO3  =  2Bi(N03).,  +  2N()  +  4H,0. 

(2)  Bi(N03),,  +  H,0  =  BiON03  -f  2HNO3. 

Other  reactions,  depending  on  the  quantity  of  water 
that  enters  the  reaction,  may  be  given. 

Bismuth     Subsalicylate     (Bismullu    Subsalicylas 


U.S.P.)— Bi(C7H303)3Bi203.  Basic  bismuth  salicy- 
late should  contain  from  62%  to  64%  of  bismuth  oxid. 
It  is  a  white,  odorless,  tasteless,  permanent,  insoluble 
powder,  partly  soluble  in  and  decomposed  by  nitric 
and  hydrochloric  acids.  It  is  prepared  by  precipi- 
tating bismuth  nitrate  with  alkah,  boiling,  adding  sali- 
cylic acid  to  the  oxid  so  obtained,  and  heating  to 
evaporation,  washing  and  drying.  Other  valuable  . 
medicinal  salts  are  the  benzoate,  oleate,  tribromate, 
phenolate  and  many  others  of  similar  kind. 

Bismuth  forms  four  oxids — bismuth  dioxid,  Bi^Oj; 
bismuth  trioxid,  61,03;  bismuth  tetroxid,  6120^;  and 
bismuth  pentoxid,  Bi^O^.  It  also  forms  a  hydroxid, 
but  does  not  form  a  trihydrid.  Most  bismuth  salts 
are  tonic,  astringent  and  antifermentative.  They 
are  largely  employed  in  intestinal  disorders.  Poison- 
ous symptoms  observed  after  using  bismuth  salts 
are  nearly  always  due  to  arsenical  impurity. 

Tests. — Neutral  and  acid  solutions  of  the  salt  are 
precipitated  by  water.  With  sulfids  it  gives  a  black 
precipitate,  alkali  hydroxids  give  a  white  precipitate ; 
iodids  give  a  brown  precipitate.  Potassium  sulpho- 
cyanate  paper  moistened  with  a  bismuth  solution 
turns  yellow  on  drying. 

COPPER.— Cuprum,  Cu.,  63.2.    Sp.  gr.,  8.9 

Occurrence. — It  is  found  native  in  large  quantities, 
notably  in  the  Lake  Superior  region  and  in  China, 
Japan  and  Sweden.  In  combination,  it  is  exceedingly 
abundant  and  is  found  in  many  forms,  chiefly  as  sulfid, 
chalcocite,  pyrites,  carbonate  (malachite)  and  cu- 
prite or  oxid.     Numerous  methods  of  separating  it 


102  PHARMACEUTIC    CHEMISTRY. 

from  its  ores  arc  employed,  all  depending  upon  the 
nature  of  the  ore. 

Properties. — It  is  a  reddish-brown  metal,  lustrous, 
very  tenacious  and  ductile,  being  readily  drawn  into 
fine  wire.  It  is  also  very  malleable,  producing  very 
thin  leaves.  It  is  fusible  and  volatile  at  very  high 
temperatures  producing  an  emerald-green  vapor.  It 
.is  readily  attacked  by  nitric  acid,  slowly  by  hydro- 
chloric and  sulfuric  acids  in  the  air,  also  very  slowly 
by  air  itself,  forming  a  green,  basic  carbonate.  Cop- 
per is  second  only  to  silver  as  a  conductor  of  electri- 
city, and  is  extensively  used  for  all  electrical  pur- 
poses. It  is  also  used  in  electrotyping  and  very 
largely  in  the  form  of  alloys,  the  most  important  of 
which  are  those  with  zinc  (brass  and  Muntz  metal), 
with  tin  (gun  metal,  bronze  and  speculum  metal), 
with  aluminum  (aluminum  bronze)  and  with  silver 
and  gold,  the  respective  coin  metals. 

Compounds. — Copper  forms  both  "ous"  and  "ic" 
compounds.  The  cuprous  oxid  is  the  only  impor- 
tant "ous"  salt  which  occurs  native,  as  red  copper 
ore,  CujO.  It  is  produced  by  the  reduction  of 
cupric  chlorid  (CuClj),  and  also  in  the  alkaline 
copper  solution  (Fehling's  solution)  with  grape 
sugar.  It  is  insoluble  in  water,  easily  affected  by 
acids  and  fuses  at  red  heat.  Copper  forms  chlorid, 
hydroxid,  oxid,  nitrate,  sulfate,  carbonate  and  sultid, 
the  only  one  retognized  officially  being  the  sulfate. 

Cupric  Sulfate  (cupri  su  fas  U.  S.  P.),  Cu  SO,. 
5H2O. — Copper  sulfate,  blue  \itriol,  blue  stone; 
purit}-,  not  less  than  g9.5'( . 


COPPER    COMPOUNDS.  I03 

Description. — Transparent,  large  deep-blue  crys- 
tals, efflorescent,  odorless  with  metallic,  astringent 
taste.  Soluble  in  2.2  parts  of  water,  3.5  parts 
of  glycerin;  insoluble  in  alcohol.  Incompatible 
with  fixed  alkali  hydroxids. 

Preparation. — (i)  By  dissolving  cupric  oxid  in 
dilute  sulfuric  acid,  filtering,  evaporating  and  crystal- 
lizing: 

CuO  +  H.SO,  =  CuSO,  +  H2O. 

(2)  By  the  action  of  hot,  concentrated  sulfuric 
acid  on  metallic  copper: 

Cu  +  2H2SO,  =  CuSO,  +  SO2  +  2H3O. 

(3)  By  roasting  copper  pyrite  in  the  air,  in  which 
process  the  sulfate  is  formed  in  conjunction  with  the 
sulfate  of  iron.  It  is  used  as  a  caustic,  astringent 
and  emetic.  A  solution  of  cupric  sulfate  in  which 
some  ammonium  chlorid  has  been  dissolved,  upon 
the  addition  of  sodium  hydroxid,  forms  cupric 
hydroxid.  This  dissolved  in  ammonia  water  forms 
Schweizer's  reagent  which  dissolves  cotton  wool  and 
other  forms  of  cellulose,  which  can  be  reprecipitated 
from  the  solution  by  the  addition  of  salts  or  acids. 

The  commercial  compounds  and  pigments  of 
copper  are  very  important.  Among  these  the  follow- 
ing may  be  named:  ^^ Paris  Green,  chemically  cupric 
acetoarsenite  (Cu(C2H302)2,  3CuO^As2);  Verdigris, 
chemically  copper  subacetate,  copper  oxyacetate, 
basic  acetate  of  copper  (Cu  (0211302)2,  2CuO  -I-3H2O). 
Copper  subacetate  is  prepared  by  exposing  copper 
to  the  action  of  acetic  acid  and  air,  and  recently 
the   term   verdigris   was   incorrectly  applied   to  the 


I04  PIlARMACEl'TIC    CHEMISTRY. 

green  carbonates  which  form  on  the  surface  of  copper 
salts.  Scheele's  Green  is  the  copper  arsenite  of  com- 
merce, a  very  valuable,  though  very  poisonous  pig- 
ment, employed  in  wall-paper  printing,  in  book  covers, 
etc.  It  is  prepared  by  mixing  solutions  of  copper 
sulfate  and  sodium  arsenite,  washing  the  bright-green 
precipitate  obtained,  and  drying.  Brunswick  Green 
is  a  mixture  of  copper  carbonate  and  chalk.  Brigh- 
ton Green  is  copper  acetate  mixed  with  chalk. 
Mountain  Green  is  the  native  copper  carbonate. 
Neiiwieder  Green,  is  a  mixture  of  Schweinfurt  green 
with  gypsum  and  barium  sulfates.  Green  vcrdites  is 
the  basic  carbonate  and  oxid  mixed  with  chalk. 

Toxicology. — Copper  salts  are  probably  falsely 
credited  with  very  poisonous  properties,  fOr  such  are 
likely  due  to  arsenical  contamination,  or  to  the  double 
salts  of  copper  and  arsenic.  Albuminous  drinks 
and  emetics  are  indicated  in  cases  of  copper  poisoning. 

Tests.— \mmon\ix.  water  produces  a  light-blue 
precipitate,  changing  to  deep  blue  solution  with 
excess.  Hydrogen  sultid  produces  a  black  precipi- 
tate (CuS).  Potassium  cyanid  produces  a  w^hite 
precipitate.  Minute  quantities  may  be  detected  by 
taking  up  with  dilute  nitric  acid,  neutralizing  with 
ammonia,  again  acidifying  with  acetic  acid,  and 
adding  potassium  ferricyanid.  A  red  color  indi- 
cates copper.  Copper  salts  color  Bunsen  flame 
green,  excepting  the  chlorid  which  colors  it  blue. 

CADMIUM- C\l,  112.  Sp.  gr.,  S.6.  Cadmium 
never  occurs  unct)nil)incd  and  is  found  in  but  few 
ores,    most    often    accomi)anying    zinc,  from    which 


it  is  obtained  by  distilling,  it  being  more  volatile  than 
the  latter. 

Description. — It  is  a  bluish-white  metal  similar 
to  zinc,  but  more  malleable  and  ductile.  It  melts 
at  320°  C.     Heated,  it  burns,  forming  brown  oxid. 

Compounds. — No  compounds  of  cadmium  are 
used  in  pharmacy.  Its  alloys  are  valuable  commer- 
cially. The  element  is  a  dyad,  forming  hydroxid, 
oxid,  chlorid,  iodid,  sulfate  and  sulfid.  Cadmium 
oxid  (CdO)  is  a  brown  salt;  the  sulfid  (CdS)  is  a 
bright-yellow  pigment  valued  as  a  paint.  The  iodid 
and  bromid  have  l^een  used  in  photography. 

MERCURIC— MERCURY.— Mercury  has  been 
fully  discussed  in  Chapter  X  (see  page  79),  and 
only  the  mercuric  compounds  that  occur  in  this 
grouping  need  here  be  discussed.  The  mercuric 
compounds  are  more  numerous  and  important. 
Mercury  plays  here  the  part  of  a  dyad  or  divalent 
element,  and  mercuric  compounds  are  always  pro- 
duced when  the  metal  is  dissolved  in  an  excess  of  the 
acid.  Mercuric  chlorid  is  an  important  salt  of 
mercury  (hydrargyri  chloridum  corrosivum,  U.  S.P.), 
HgClg,  also  called  bichlorid,  perchlorid,  muriate 
and  corrosive  sublimate.    • 

Preparation. — By  subliming  a  dry  mixture  ol 
mercuric  sulfate  and  sodium  chlorid.  HgSO^-l- 
2NaCl  =  HgCl,  -f  NajSOj.  The  sublimed  form  is 
that  of  rectangular  octahedra;  while  that  crystallized 
from  a  solution  assumes  rhombic  prism  form.  It  is, 
therefore,  dimorphous.  It  is  soluble  in  16  parts  of 
water,  14  parts  of  glycerin,  3  of  alcohol.     In  presence 


Io6  PHARMACEUTIC    CITE \r  1ST RV 

of  heavy  metals  it  is  reduced  to  the  mercurous  state 
(calomel).  Its  aqueous  solution,  treated  with  an 
alkaline  hydroxid  (lime  water),  produces  a  yellow- 
precipitate  of  mercuric  oxid  (HgO),the  liquid  so 
produced  being  known  as  "yellow  wash"  (lotio  flava, 
N.  F.,  or  "aqua  phagedenica  tlava  "  of  the  ancients). 
Yellow  mercuric  oxid  (hvdrargyri  oxidum  flavum 
U.  S.  P.)  is  })repared  by  precipitating  mercuric 
chlorid  solution  with  sodium  hydroxid.     Reaction: 

HgCls  +  2NaOH  =  HgO  +  2NaCl  +  H2O. 
An  orange-yellow,  amorphous,  insoluble  powder, 
soluble  in  dilute  acids.  It  is  more  active  than  the 
red  oxid  and  therefore  preferred  in  skin  prepara- 
tions and  eye  salves.  Ammoniated  mercury  (hydrar- 
gyrum ammoniatum  U.  S.  P.),  NH.HgCM,  white 
precipitate,  ammoniated  chlorid  of  mercury,  amido- 
chlorid  of  mercury,  is  produced  by  mixing  solutions 
of  mercuric  chlorid  and  ammonia  water,  washing 
the  precipitate  with  water  containing  a  little  am- 
monia and  drying.  Reaction: 
2NH,OH  +  HgCU  =  NH.HgCl  +  NH.Cl  +  2W^O. 
It  is  an  insoluble,  white  powder,  soluble  in  warm 
hydrochloric  or  nitric  acids. 

Red  mercuric  iodid  (hydrargyri  iodidum  rubrum 
U.S.  P.),  Hgl.,  red  iodid,  biniodid,  deutoiodid. 
mercuric  iodid. 

Preparation. — Made  by  mixing  solutions  of  mer- 
curic chlorid  and  potassium  iodid,  washing  free  from 
chlorids  and  drying  the  precipitate.     Reaction: 

HgCU  +  2KI  =  Hgl,,  +  2KCI. 
It    is    a    scarlet-red    ])owder,     usually    amor|)hous, 


MERCURIC    OXID.  107 

sometimes  found  in  octahedral  and  rhombic  needles, 
hence  is  dimorphous.  It  dissolves  in  a  solution  of 
potassium  iodid  or  mercuric  chlorid.  It  is  nearly 
insoluble  in  all  other  solvents.  It  is  an  ingredient 
of  Donovan's  solution  (liquor  arseni  et  hydrargyri 
iodidi  U.  S.  P.). 

Red  mercuric  ox  id  (hydrargyri  oxidum  rubrum 
U.  S.  P.),  HgO,  red  precipitate,  peroxid. 

Preparation. — By  heating  nitrate  of  mercury 
crystals  till  nitrous  fumes  cease  to  evolve.  It  is  a 
red  powder  or  crystalline  scale.  By  dissolving  it  in 
hydrochloric  acid  and  evaporating,  the  mercuric 
chlorid  is  obtained.  The  difference  in  the  two  oxids 
— yellow  and  red — lies  in  the  methods  of  their 
preparation,  the  former  made  by  precipitation,  the 
latter  by  ignition  of  the  nitrate.  Students  should 
remember  that  there  is  one  each  official — a  mer- 
cnrous  and  a  mercuric  chlorid  and  iodid — but  that 
both  the  oxids  have  the  same  composition,  both 
being  mercuric  salts.  They  are  both  insoluble  in 
ordinary  solvents,  but  soluble  in  dilute  acids. 
Among  the  unofficial  mercuric  compounds  are  the 
cyanid  (HgCNj)  a  very  poisonous,  opaque-white 
mass,  soluble  in  12  parts  of  water;  turpeth  mineral 
(hydrargyri  subsulfas  flavus),  Hg(HgO)S04,  basic 
sulfate  of  mercury,  a  lemon-yellow  powder  used 
as  an  emetic;  mercuric  nitrate  Hg(N03)2,  pre- 
pared by  careful  solution  of  mercury  or  of  the  oxid  in 
nitric  acid.  It  is  used  as  a  reagent  in  "Liebig's 
urea  test"  and  for  preparing  other  compounds  of 
mercurv. 


CHAPTER   XIII. 
IRON,  ALUMINUM,  CHROMIUM. 

The  amuwnium  siilfid  group  embraces  those 
metals  which  are  precipitated  by  ammonium  sulfid 
solution.  The  entire  group  is  subdivided  into  two 
divisions:  iron,  aluminum  and  chromium  com- 
prise the  first  division,  and  cobalt,  nickel,  man- 
ganese and  zinc  make  up  the  second  division.  The 
reason  for  this  division  is  that  while  ammonium  sul- 
fid precipitates  all  the  seven  metals,  it  does  not  form 
the  same  compounds  with  all.  Thus,  the  metals  of 
the  first  division  are  precipitated  as  hydroxids,  while 
those  of  the  second  division  are  precipitated  as  sul- 
fids.  Moreover,  the  first  division  may  be  precipi- 
tated by  ammonium  hydroxid  in  the  presence  of  am- 
monium chlorid,  which  latter  i)revents  the  precipita- 
tion of  the  remaining  metals.  Thus,  the  first  three 
metals  are  separated  from  the  second  division  as 
hydroxids.  If  ammonium  sulfid  is  now  added 
to  the  entire  division,  it  changes  the  iron  hydroxid  to 
a  sulfid,  but  does  not  affect  the  remaining  two. 

IRON. — Ferrum,  Fe,  56.     Sp.  gr.,  7.1  to  8.1. 

Occurrence. — Iron  is  found  native  in  small  quan- 
tities in  the  meteorites,  in  some  to  the  extent  of  98%. 
It  is  a  metal  of  great  importance  and  is  widely  dis- 
tributed. The  ores  that  contain  iron  in  combination 
are  numerous,  but  only  few  of  the  more  important 
108 


IRON.  109 

ones  will  be  here  mentioned.  Magnetite,  Fefi^ 
consists  of  ferroso-ferric  oxid  =  FeO,  Fe203;  He- 
matite, chiefly  ferric  oxid,  FcjOg;  Limonite  (or  brown 
hematite),  a  variable  mixture  of  the  oxid  and  hy- 
droxid,  and  Siderite  (spathic  iron),  consists  of  ferrous 
carbonate,  FeCOg.  The  sulfur  ores,  as,  for  example, 
the  iron  pyrites  (FeS^,),  are  not  well  adapted  to  ex- 
traction, but  are  valuable  for  the  manufacture  of  the 
acids  of  sulfur. 

Preparation. — Iron  exists  in  three  forms — as  cast 
iron,  wrought  or  malleable  iron  and  steel.  To 
understand  the  relationship  existing  between  these  it 
is  best  to  study  the  processes  of  their  manufacture. 
The  ore  in  case  of  the  hematites  is  first  calcined  to 
remove  the  water,  and  in  case  of  the  carbonate  ores, 
the  carbon  dioxid.  The  calcined  ore  consists  chiefly 
of  ferric  oxid  and  it  is  smelted  in  blast  furnaces 
with  limestone  and  coke.  Limestone  forms  a  fusible 
slag  with  the  silica  present  while  the  coke  burns 
in  the  hot  air  introduced  by  the  blast  tubes,  forming 
carbon  monoxid,  which  serves  as  a  reducing  agent 
of  the  glowing  ferric  oxid  to  metallic  iron.     Reaction: 

Fe^Oj  +  3CO  =  Fe,  +  3CO2. 
The  smelting  is  continued  uninterruptedly,  the  fur- 
nace being  supplied  with  fresh  material  so  that  molten 
iron  is  continuously  formed  at  the  bottom  of  the 
furnace  from  which  it  is  drawn  off  from  time  to 
time  at  a  special  tap-hole  which  is  temporarily 
blocked  up  with  clay,  while.the  slag  of  calcium  silicate 
floating  on  the  .surface  of  the  molten  iron  is  allowed  to 
flow  away  as  soon  as  it  forms.     The  iron  is  run  into 


no  PHARMACEUTIC    CHEMISTRY. 

channels  made  in  sand,  in  which  it  sohdifies  in  bars 
known  in  commerce  as  pig  iron  or  cast  iron.  Since 
cast  iron  is  produced  in  contact  with  carbon,  it  con- 
tains a  small  amount  of  this  element,  both  as  ferric 
carbid  and  in  the  free  state.  Besides  these,  it  usu- 
ally contains  silicon,  phosphorus,  some  sulfur  and  a 
little  manganese.  Cast  iron,  containing  from  2  to 
5%  of  carbon,  is  comparatively  brittle,  easily  fusible 
and  cannot  be  welded.  By  removing  the  silicon, 
phosphorus,  sulfur,  etc.,  which  exist  there  as  imj)uri- 
ties,  we  produce  wrought  iron  which  is  a  compara- 
tively pure  form  of  iron.  This  is  done  by  piling  pig 
iron  on  the  bed  of  a  reverberatory  furnace  previously 
lined  with  ferric  oxid,  melting  and  thoroughly  stirring 
the  iron,  when  the  impurities  will  become  oxidized 
through  the  ferric  oxid  lining  in  the  furnace,  and  will 
escape  as  sulfur  dioxid,  carbonic  acid,  phosphorus 
oxid,  etc.  Wrought  iron  contains  less  than  0.2% 
of  carbon,  is  extremely  malleable,  infusible  in  the 
ordinary  furnace,  tough,  and  when  heated  to  white 
heat  it  becomes  pasty,  so  that  two  pieces  when  brought 
together  while  hot  and  hammered  can  be  welded 
into  one.  Steel  is  produced  by  heating  bars  of 
wrought  iron  imbedded  in  layers  of  charcoal  for  sev- 
eral days,  in  which  process,  although  the  iron  never 
melts,  the  carbon  permeates  it  to  the  extent  of  0.5  to 
1.4%.  This  process  is  now  employed  only  for  the 
production  of  high-quality  steel,  and  has  been  super- 
seded by  the  cheaper  Bessemer  process.  This  con- 
sists in  blowing  a  current  of  air  through  molten  cast 
iron   until  the  impurities  are  burned  out.     To  this 


purified  metal  a  certain  proportion  of  pure  pig  iron, 
preferably  that  containing  manganese,  like  spiegel- 
eisen  or  jerromanganese,  is  added,  together  with  a 
certain  quantity  of  carbon.  The  carbon  converts 
the  iron  into  steel  and  the  manganese  serves  to 
neutralize  the  untoward  effects  due  to  the  small 
quantities  of  the  oxids  present.  Steel  is  now  manu- 
factured largely  by  the  so-called  "open  hearth" 
method  or  Siemens-Martin  process.  This  process 
consists  in  fusing  cast  iron  in  a  reverberatory  furnace 
much  as  in  the  puddling  process,. next  adding  wrought 
iron  to  it  and  a  small  quantity  of  spiegeleisen,  until 
the  percentage  of  carbon  is  raised  from  0.3  to  1.4%. 

Steel  contains  from  0.3  to  1.5%.  of  carbon  which 
is  chemically  combined  with  the  iron.  It  has  a 
fine-grained  structure;  it  is  malleable  and  fusible 
in  a  furnace  with  a  good  draught;  it  melts  at  about 
1400°  C.  Its  most  important  property  is  that  it  can 
be  tempered,  that  is,  its  hardness  may  be  altered  by 
the  rate  at  which  it  is  cooled.  If,  for  example,  when 
heated  to  redness,  it  is  plunged  into  cold  water,  it  is 
very  brittle,  but  hard  enough  to  scratch  glass; 
if,  however,  it  be  allowed  to  cool  gradually,  it  is 
almost  as  soft  and  malleable  as  wrought  iron.  From 
the  above  it  will  be  seen  that  the  tensile  strength  of 
pure  iron  is  greatly  increased  by  the  admixture  of 
small  quantities  of  carbon,  and  the  so  carbonized  iron 
is  called  steel. 

Spiegeleisen  (mirror  iron)  is  a  white,  very  crystal- 
line cast  iron,  containing  manganese  as  its  chief 
constituent. 


112  PHARMACKUTIC    CHEMISTRY. 

Description. — Iron  is  a  soft,  white,  lustrous  metal 
with  greatest  magnetic  and  tenacious  power.  It 
fuses  with  difficulty,  but  welds  easily.  It  is  fibrous 
in  structure,  but  becomes  crystalline  in  time  from 
continuous  vibrating  or  jarring,  in  which  case  it  has 
much  less  tenacity.  In  dry  air  it  is  oxidized  only 
at  high  temperature.  It  will  not  oxidize  in  pure, 
water,  but  in  moist  air  or  when  placed  in  water 
which  has  absorbed  CO,  from  the  air,  it  oxidizes 
quickly,  the  change  being  commonly  called  ''rusting." 
In  contact  with  magnets,  it  becomes  itself  magnetic, 
but  only  tempered  steel  will  retain  this  property  for 
any  length  of  time.  Hydrochloric  and  sulfuric  acids 
dissolve  it  freely  and  dilute  nitric  acid  fairly  easily, 
but  concentrated  nitric  acid  stops  all  solution  till 
the  "passive"  condition  is  removed  by  heat  or  by 
coatact  with  certain  metals. 

Compoiinds. — Iron  forms  both  "ic"  compounds, 
in  which  it  is  trivalent,  and  "ous"  compounds,  in 
which  it  is  divalent. 

It  is  official  in  two  forms: 

Iron  (ferrum  U.  S.  P.),  metallic  iron  in  the  form 
of  fine,  bright  and  non-clastic  wire  (card  teeth);  and 

Reduced  iron  (ferrum  reductum  U.  S.  P.\  iron 
by  hydrogen,  alcoholized  iron,  Quevciinos  iron,  con- 
taining at  least  90%  pure  iron.  It  is  a  line,  grayish- 
black  powder,  made  by  heating  iron  liydroxid  in 
h\drogen.     Reaction: 

2Fe(OH)3  +  3H,  =  Fc.,  -h  6H,0. 

Sdcclia rated  iron  carbonate  (ferri  carbonas  sac- 
charatus   U.  vS.P.)  should  contain  not  less  than  15% 


FERROUS    SULFATE.  II3 

of  FeCOg.  It  is  a  greenish-gray  powder,  sweetish, 
iron-like  taste,  not  permanent,  and  should  be  kept  in 
small,  closely  stoppered  bottles.  It  is  a  mixture  of 
sugar  and  ferrous  carbonate,  the  latter  prepared  by 
double  decomposition  between  ferrous  sulfate  and 
sodium  bicarbonate.  Reaction: 
FeS04  +  2NaHC03=FeC03-fNa2S04  +  H,0+C02. 
The  carbonate  of  iron  is  an  ingredient  in  the  pill, 
mass  and  iron  mixture  of  the  U.  S.  P.  preparations. 

Iron  sulfate  (ferri  sulfas  U.  S.  P.),  FeSO^  -|- 
7H2O.  Green  vitriol,  copperas,  ferrous  sulfate. 
Large,  bluish-green  colored  crystals,  soluble  in  0.9 
parts  of  water,  and  containing  at  least  99.5%  of 
FeS04.  It  is  made  by  dissolving  iron  in  dilute  sul- 
furic acid:  Fe  +  H2SO4  =  FeSO^  +  Hj.  It  is  used 
as  a  disinfectant  in  the  arts  and  for  the  production 
of  the  ofi&cial  dried  and  granulated  iron  sulfates. 

Dried  jerrous  sulfate  (ferri  sulfas  exsiccatus 
U.  S.  P.),  FeSO^.  A  white  or  gray  powder,  made  by 
heating  ordinary  ferrous  sulfate  until  it  loses  35% 
in  weight.     It  should  be  kept  well  stoppered. 

Granulated  ferrous  sulfate  (ferri  sulfas  granulatus 
U.  S.  P.),  FeSO„  7H2O,  was  ofi&cial  in  the  U.  S.  P., 
'90,  as  "precipitated"  ferrous  sulfate.  It  is  merely 
a  granular  form  of  ferrous  sulfate  made  by  dissolving 
the  commercial  salt  in  hot  water  containing  a  little 
sulfuric  acid,  filtering,  evaporating,  chilling  suddenly, 
draining  the  salt  on  a  filter,  washing  with  alcohol  and 
permitting  it  to  dry  in  an  atmosphere  of  alcohol. 

Other  ferrous  compounds  are  the  lactate  (Fe- 
(CgHsOg).),  tartrate    (FeC^H^Og),  phosphate  {Fe^- 


114  PHARMACEUTIC    CHEMISTRY. 

(POJj),  oxalate  (FeQO;),  chlorid  (FeCU),  iodid 
(Felj),  this  'ast  salt  being  the  ingredient  of  the  official 
syrup  and  pil  of  iron  iodid  (syrupus  ferri  iodidi) ;  oxid 
(FeO)  and  hydroxid  (Fe(OH)2),  all  possessing  the 
usual  properties  of  iron  combined  with  the  character- 
istics of  the  acid  from  which  formed. 

The  ferric  compounds  are  more  numerous  and 
important  than  the  ferrous  compounds. 

Ferric  chlorid  (ferri  chloridum  U.  S.  P.),  FeClg 
+  12H2O,  muriate,  perchlorid,  or  sesquichlorid  of 
iron.  Orange-yellow,  crystalline  masses  or  crusts, 
made  by  crystallizing  a  properly  oxidized  solution 
of  ferric  chlorid.  A  very  deliquescent  salt  used  as 
a  chalybeate.  It  is  made  by  dissolving  iron  wire  in 
HCl  and  oxidizing  the  solution  with  HNO3: 

(i)  Fe^  +  4HCI  =  2FeCl2  -f  2H2. 

(2)  6FeCl.,  +  6HC1  +  2HNO3  =  6YeC\^  +  4H2O 
-I-  2(NO). 

An  aqueous  solution  of  ferric  chlorid  is  official 
(liquor  ferri  chloridi  U.  S.  P.).  This  solution  should 
contain  about  37.8%  of  anhydrous  FeClg,  correspond- 
ing to  about  62.9%  of  the  crystallized  salt.  A  tinc- 
ture of  ferric  chlorid  (tinctura  ferri  chloridi  U.  S.  P.), 
made  by  diluting  the  solution  with  alcohol,  is  also 
official.  The  tincture  should  contain  at  least  13.28% 
of  anhydrous  salt  which  corresponds  to  4.6%  of 
metallic  iron. 

Ferric  hydroxid  (ferri  hydroxidum  U.  S.  P.), 
Fe(OH)3,  ferric  hydrate,  peroxid,  hydra  ted  ferric 
oxid.  Prei)ared  by  precipitating  a  solution  of  ferric 
chlorid  with  ammonia  water  and  washing  free  from 


SCALE    SALTS.  II5 

the  ammonium  chlorid  formed;  a  brownish  magma 
results.     Reaction: 

FeClg  +  3NH,0H  =  FeCOH),  +  3NH,C1. 

Ferric  hydroxid  with  magnesium  oxid  (ferri  hy- 
droxidum  cum  magnesii  oxido  U.  S.  P.) — "arsenic 
antidote."  This  should  be  freshly  made  if  it  is  to 
be  used  as  an  antidote  in  arsenical  poisoning. 

Preparation. — By  rubbing  MgO,  lo  gm.,  in  H2O, 
800  c.c,  gradually  adding  a  mixture  of  ferric  tersul- 
fate  solution,  40  c.c,  and  HjO,  125  c.c,  and  mixing 
thoroughly.     Dose,  120  c.c. 

Ferric  hypophosphite  (ferri  hypophosphis  U.  S.  P.), 
Fe(PH202)2.  A  grayish-white  powder,  nearly  taste- 
less and  slightly  soluble.  Used  in  making  syrup  of 
hypophosphites  comp.  (syrupus  hypophosphitum 
compositus  U.  S.  P.).     Used  as  a  hematinic 

Iron  and  ammonium  stdfate  (ferri  et  ammonii 
sulphas  U.  S.  P.),  FeNH,(S0,)2  +  12H2O.  Iron 
and  ammonia  alum,  iron  alum.  Pale  violet^  octa- 
hedral crystals,  odorless,  styptic  taste,  efflorescent. 
Should  contain  99.5%  pure  salt,  corresponding  to 
11.5%  of -iron.  Prepared  by  dissolving  ammonium 
sulfate  in  solution  of  ferric  tersulfate,  evaporating 
and  crystallizing.     Reaction: 

Fe2(SO,)3  -f-  (NH,)2SO,  =  2FeNH,(SO,)2. 

SCALE  SALTS. — These  compounds  are  usually 
prepared  by  dissolving  ferric  hydroxid  in  a  corre- 
sponding organic  acid,  evaporating  to  syrupy  consist- 
ence and  spreading  on  glass  plates,  from  which  it 
flakes  or  scales  on  cooling.  All  scale  salts  are  ferric 
salts. 


Il6  PHARMACEUTIC    CHEMISTRY. 

There  are  nine  official  scale  salts:  Soluble  ferric 
phosphate  (fcrri  phosphassolubilis),iron  12%  ;  soluble 
ferric  pyrophosphate  (ferri  pyrophosphas  solubilis), 
iron  10%;  ferric  citrate  (ferri  citras),  corresponding 
to  16%  iron;  iron  and  ammonium  citrate  (ferri  ct 
ammonii  citras),  corresponding  to  16%  iron;  iron  and 
ammonium  tartrate  (ferri  et  ammonii  tartras),  corres- 
ponding to  13%  iron;  iron  and  potassium  tartrate 
(ferri  et  potassii  tartras),  15%  iron;  iron  and  quinine 
citrate  (ferri  et  quinins  citras),  13.5%  iron;  soluble 
iron  and  quinine  citrate  (ferri  et  quininae  citras  solu- 
bilis), i3.5'/(  iron;  iron  and  strychnine  citrate  (ferri 
et  strychnina;  citras),  16%  iron.  The  soluble  phos- 
phate and  pyrophosphate  are  green  in  color,  the 
other  seven  being  garnet-red  to  reddish-brown. 
With  the  exception  of  iron  citrate  and  the  iron  and 
quinine  citrate,  which  are  very  slowly  soluble  in  water, 
all  the  scale  salts  of  iron  contain  alkalin  citrate  or 
tartrate,  purposely  added  to  enhance  their  solubility, 
and  are  usually  designated  as  "soluble." 

All  the  official  liquors  of  iron  contain  ferric  salts. 

Dialysed  iron  (ferrum  dialysatum)  is  made  by 
dissolving  crystalline  ferric  chlorid  in  the  solution  of 
ferric  chlorid  and  subjecting  the  mixture  to  dialysis, 
liy  this  ])roccss  the  remaining  free  acid  is  removed, 
leaving  a  colloidal  basic  salt  composed  of  99%  of 
ferric  hydroxid  and  1%  of  hydrochloric  acid. 

Iron  and  its  salts  are  not  poisonous. 

Tests. — Iron  may  be  detected  by  a  red  ]>recipitate 
with  ammonium  hydroxid,  a  bnnvnish-black  pre- 
cipitate with  hydrogen  sulfid.  et(  . 


ALUMINUM.  I  I  7 

Distinctive  tests  between  jerric  salts  and  jcrroiis 
salts: 

REAGENT  FERRIC    SALTS.  FERROUS    SALTS. 

Potassium  ferrocyanid,  Dark-blue  precipitate  Light-blue  precipitate 
Potassiurri  ferricyanid,  Brownish    color;  no     Dark -blue  precipitate. 

precipitate  formed. 

Potassium  sulfocyanid,  Dark,  blood-red  color-  No    change    of    color 

ation.  (with  impure  ferrous 

salts  turns  reddish). 

Alkalis,  Brownish  precipitate.  Green      precipitate, 

turning    brown    on 
the  surface. 

ALUMINUM,  Al,  27.     Sp.  gr.,  2.5. 

Occurrence. — Aluminum  is  the  most  abundant 
metal,  and  of  all  the  elements  it  is  only  exceeded 
in  abundance  by  oxygen  and  silicon.  It  is  never 
found  native  and  until  comparatively  recently  it  was 
difficult  to  extract  from  its  combinations.  It  occurs 
as  a  silicate  in  clays,  kaolin,  feldspars,  micas,  granite, 
porphyry  and  many  crystalline  rocks.  As  an  oxid 
(AI2O3),  it  is  found  in  the  ruby,  sapphire  and  in 
corundum  and  emery.  Cryolite  is  the  double  fluorid 
of  aluminum  and  sodium  (Al2Clg,6NaCl),  and 
bauxite  is  an  hydrated  oxid  (Al203,H20),  both  of 
which  are  largely  used  for  the  production  of  aluminum. 

Preparation. — (i)  By  reducing  of  the  ores  with 
carbon  by  the  intense  electric -furnace  heat;  (2)  by 
treating  cryolite  with  metallic  sodium  (Deville's 
process).     Reaction: 

Al2Cle,6NaCl  +  aNa,  =  W,  -f  12  NaCl 
Cryolite 

Properties. — A  white,  silvery  metal,  very  tenacious, 
malleable  and  ductile.  It  is  very  light,  but  strong 
and  rigid;  is  an  excellent  conductor  of  heat  and 
electricity,  almost  equal  to  silver  in  this  respect. 
It  is  affected  but  little  by  air,  gases    or   ordinary 


Il8  PHARMAt'EUTIC    CHKMISTRY. 

acids,  but  is  readily  dissolved  by  caustic  alkalis.  It 
melts  at  625°  C.  It  does  not  tarnish  in  the  air  and 
is  not  affected  by  hydrogen  sulfid.  Aluminum  forms 
valuable  alloys  and  is  much  used  in  the  arts.  It  is 
also  becoming  of  great  value  in  numerous  commercial 
and  domestic  wares. 

Aluminum  bronze  (copper,  90;  aluminum,  10), 
is  one  of  the  alloys  of  aluminum  valued  for  castings 
and  superior  to  brass  in  tensile  strength.  Steel  is 
improved  by  the  addition  of  0.1%  of  aluminum. 

Aluminum  acts  as  a  trivalent  element. 

The  alums  are  important  compounds  of  aluminum. 
The  general  formula  of  the  alums  is  RR'(S04)2, 
12H2O — the  R  representing  Al,  Cr,  Fe  or  j\In,  and 
R'  one  of  the  alkali  metals.  They  all  crystallize  as 
octahedra. 

Akim  (alumen  U.  S.  P.),  A1K(S04)2  +  12H2O. 
Alum,  potash  alum.  Purity,  99.5%.  Large,  odor- 
less, colorless,  octahedral  crystals,  with  astringent 
taste.  Soluble  in  9  parts  of  water.  Incompatible 
with  alkali  hydroxids,  carbonates  and  phosphates, 
and  chlorids  of  the  heavy  metals.  Other  alums  are 
the  ammonia  alum,  AINH^(S04)2  +  laHjO,  simi- 
lar to  potash  alum,  a  double  sulfate  of  ammonium; 
iron  alum,  chrome  alum,  manganese  alum,  etc.,  in 
which  these  respective  metals  replace  the  aluminum 
in  the  molecule. 

Preparation. — Official  alum  is  made  by  calcining 
alum-shale  (alum  clay,  aluminum  silicate)  with 
iron  pyrites,  which  operation  results  in  the  forma- 
tion of  sulfuric  acid,   which  acting  on  the  silicate 


ALUMINUM   COMPOUNDS.  II9 

produces  aluminum  sulfate.  This,  together  with  the 
sulfates  of  iron  is  extracted  with  water.  In  this 
liquid  potassium  chlorid  is  dissolved  which  interacts 
with  the  iron  sulfates,  becoming  converted  into 
potassium  sulfate,  which  combines  with  aluminum 
sulfate  and  which  crystallizes  with  12  molecules 
of  water  of  crystallization. 

Exsiccated  Alum  (alumen  exsiccatum  U.  S.  P.)' 
AlK(SOj2,  dried  or  burnt  alum,  alumen  ustum- 
Purity,  99%.  A  dry,  porous  mass  or  powder,  odor- 
less, sweetish,  astringent  taste,  nearly  twice  as  strong 
as  the  official  alum,  attracting  moisture.  It  is  soluble 
in  17  parts  of  water,  1.5  parts  of  boiling  water. 

Preparation. — By  merely  driving  off  the  water  of 
crystallization  from  alum.  The  alums  are  all  used 
as  caustic  astringents. 

Aluminum  salts  precipitate  organic  colors,  forming 
with  them  pigment  "lakes,"  etc.  This  important 
property  is  utilized  in  dyeing,  where  alumina 
(Al(OH)3)  becomes  deposited  in  the  material  to  be 
dyed  and  acts  as  a  "mordant,"  "binder"  or 
"fixer"  of  the  dyes  employed. 

Aluminum  hydroxid  (alumini  hydroxidum  U.  S.  P.), 
Al(OH)3,  alumina.  A  white,  light,  amorphous 
powder,  permanent,  odorless  and  tasteless,  made  by 
treating  a  soluble  salt  of  aluminum  with  an  alkali 
hydrate  or  carbonate:  2AIK(S04)2  +  aNajCOg  + 
3H2O  =  2AI(OH)3  +  K2SO,  +  sNa^SO,  +  3CO3. 
It  is  used  as  a  mechanical  protective  filtering  me- 
dium and  for  preparing  the  sulfate  of  aluminum. 

Aluminum  sulfate  (alumini  sulphas  U.  S.  P.),  Al,- 


I20  I'llARMACFAITIC    CIIK.M  ISTKY. 

(804)3  +  ibHjO;  99.5%  pure.  It  is  a  white,  crys- 
talline powder,  flakes  or  fragments,  odorless,  sweet- 
ish, astringent  taste,  soluble  in  one  part  water.  Loses 
crystalline  form  at  200°  C.  In  medicine,  aluminum 
sulfate  should  not  be  confounded  with  alum.  A 
commercial  aluminum  sulfate  (alum  cake)  is  some- 
times called  "concentrated  alum"  and  contains 
but  12  molecules  of  water  of  crystallization. 

Aluminum  forms  chlorid  (AICI3),  oxid  (AljOg), 
bromid  (AlBrg),  iodid  (AII3),  fluorid  (AIF3).  Spinel 
is  native  magnesium  aluminate  (MgAljO^).  Other 
aluminates  are  known,  but  they  find  but  little  appli- 
cation in  the  arts. 

The  most  important  utilization  of  the  aluminum 
clays  is  in  pottery  and  ceramics.  Thus,  porcelain, 
earthenware  and  stoneware  are  prepared  from 
native  aluminum  compounds;  porcelain  from  kaolin, 
feldspar  or  quartz;  earthenware  from  clay  or  feld- 
spar and  silica;  stoneware  from  clay  containing  ferric 
oxid  and  lime.  Cements  and  mortars,  which  are 
manufactured  from  the  lime-clays  and  similar  arti- 
ficial mixtures,  may  here  be  mentioned: 

When  burnt  (calcined)  lime  is  treated  with  water, 
it  "slakes."  When  such  slaked  lime  is  alone  used 
as  a  mortar,  it  sets  and  slowly  hardens,  but  in  the 
process  of  setting  it  cracks,  thus  making  its  use  as 
mortar  unprofitable.  When,  however,  it  is  mixed 
with  some  substance  which  tends  to  counteract  this 
excessive  shrinkage,  it  forms  a  good  mortar.  Sand  or 
silica  (SiO,)  is  a  good  admixture  for  this  purpose  if 
mixed  with  the  lime  in  proper  proportions.     The 


setting  of  mortar  is  due  to  the  loss  of  moisture  (water 
is  formed  in  the  process  of  setting,  thus:  Ca(OH)2  + 
CO2  =  CaCOg  +  H,0,  this  accounting  for  the  per- 
sistent dampness  of  newly  built  houses  in  which 
the  mortar  is  setting),  and  the  hardening  is  due  to 
absorption  of  carbon  dioxid  from  the  air  which  in 
time  converts  the  lime  to  limestone.  In  this  reaction 
the  lime  superficially  attacks  the  surfaces  of  the  sand 
grains,  converting  these  into  calcium  silicate  which 
further  solidifies  the  mortar,  making  it  in  time  a 
stone-like  mass.  For  this  purpose  angular  sand 
grains  are  preferred  to  the  well-rounded  pebbles. 

Roman  cement  is  made  by  calcining  calcareous 
clay  which  must  be  "fat"  (free  from  magnesia)  at 
a  temperature  just  below  sintering. 

Portland  or  hydraulic  cement  is  made  by  calcining 
mixtures  of.  limestone  with  clay  (or  other  materials 
containing  aluminum,  silica  and  lime)  and  finely 
grinding  ■  the  resulting  clinker-like  mass.  When 
mixed  with  water,  cement  should  not  be  allowed  to 
stand,  but  should  be  appHed  at  once.  The  setting 
of  cement  is  supposed  to  be  due  to  the  formation  of 
crystalHne  silicates  and  aluminates  of  calcium,  which 
form  a  hard  stone-like  mass.  Good  Portland  cement 
should  contain  from  55  to  60%  of  lime,  22  to  26% 
of  silica  and  7  to  8%  of  alumina. 

Concrete  consists  of  hydraulic  cement  mixed  with 
crushed  rock  or  pebbles. 

Aluminum  and  its  salts  are  nonpoisonous. 

Tests. — Aluminum  may  be  detected  by  precipi- 
tation with  ammonia,  as  hydroxid  soluble  in  alkali 


122  PHARMACiaTTIC    CHEMISTRY. 

hydroxids  and  rejjrecipated  hy  NH^CI;  alsci  by  fusion 
on  charcoal  with  cobalt  nitrate,  giving  a  rich  blue 
color  to  the  mass. 

CHROMIUM,  Cr,  52.     Sp.  gr.,  6.8. 

Occurrence. — Chromium  is  not  found  free,  but 
occurs  most  commonly  in  chromite,  also  called 
"chrome  iron  ore,"  a  ferrosochromic  oxid,  Cr203- 
FeO.  It  is  separated  with  difficulty  from  the  ore, 
and  is  usually  prepared  by  the  reduction  of  chromium 
sesquioxid  with  charcoal  in  the  electric  furnace. 

Properties. — It  is  a  hard,  glistening,  steel-gray 
metal,  very  fusible,  magnetic  at  low  temperatures, 
oxidizes  only  at  a  high  heat,  is  soluble  in  hydrochloric 
acid  and  strong  alkalis. 

Alloys  of  chromium  are  admixed  with  steel  to 
increase  the  strength  of  the  latter. 

Chromium  acts  both  as  an  acid  and  a  basic 
radical,  forming  compounds  in  each  capacity.  As 
a  base  it  exerts  trivalent,  tetravalent  and  h^exavalent 
properties,  forming  "ous"  and  "ic"  salts.  It  forms 
two  oxids  well  defined — the  chromic  oxid  (CrjOj), 
a  green,  insoluble  powder  used  as  pigment  in  glass 
and  porcelain  making;  and  chromic  anhydrid  or 
trioxid  (chromii  trioxidum)  (CrOg),  previously  im- 
properly known  as  "chromic  acid." 

Preparation. — From  ])otassium  dichromate  and 
sulfuric  acid:  KjCr,©;  +  HjSO,  =  2Cr03  -\-  K2SO, 
+  H2O.  Saffron-colored  needle  crystals,  very  hy- 
groscopic, very  strong  oxidizing  agent.  Decom- 
poses organic  solvents,  such  as  alcohol  or  glycerin, 
with  dangerous  violence.     It  is  used  as  a  caustic. 


CHROMIUM.  123 

With  water  it  forms  cliromic  acid  (H^CrO^),  from 
which  a  series  of  salts  are  produced:  H,0  +  CrOg 
=  HjCrO^.  A  second  acid  may  be  produced  by 
removing  water  from  ordinary  chromic  acid.     Thus: 

2H,CrO,  —  H2O  =  H2Cr207, 
the  series  of  salts  are  known  as  dichromates  (bi- 
chromates), and  the  principal  one  is  the  potassium 
salt — potassium  dichromate,  also  called  bichromate 
or  red  chromate  (potassii  dichromas  U.  S.  P.), 
K,Cr,07    (K,CrO,,Cr03). 

Potassium  dichromate  is  prepared  from  potassium 
chromate  and  su'furic  acid.     Reaction: 

aK^CrO^  +  H^SO,  =  K^Cr^O^  +  K^SO,  +  H^O. 
It  occurs  as  a  reddish,  crystalline  salt. 

Potassium  chromate,  K2CrO^  yellow  chromate 
of  potash,  is  made  by  roasting  chrome  iron  ore  with 
potassium  carbonate  and  lime.     Reaction: 

2FeO,Cr203  +  3K2CO3  +  CaO  +  70  =  CaCrO, 
+  Fe^Og  +  3K,CrO,  +  3CO,. 

The  yellow  chromate  is  more  soluble  than  the  di- 
chromate; both  salts  are  much  used  in  the  arts  and 
chemically  as  strong  oxidizing  agents,  especially  the 
latter.  Lead  chromate  (chrome  yellow),  PbCrO^,  is 
found  native  as  crocoisite.  It  is  prepared  by  pre- 
cipitating soluble  lead  salt  with  potassium  dichromate; 
barium  chromate,  BaCrO^,  is  prepared  similarly. 
Both  are  used  as  yellow  pigments. 

Chromic  sulfate  (chrome  alum)  has  the  formula 
CrK(S04)2,i2H20.  By  adding  ammonia  to  chrome 
alum  the  greenish  hydroxid  Cr(0H)3  is  obtained, 
which  on  ignition  yields  the  sesquioxid  Cr203,  which, 


124  PllAKMACF.UTlC    CHKMISTRV. 

under  tlie  name  of  chrome  green,  is  employed  as  a 
green  pigment.  Another  pigment  is  "Guignet's 
Green,"  a  hydroxid  obtained  by  heating  potassium 
dichromate  with  boric  acid  and  extracting  with  water. 
Both  the  yellow  and  green  pigments  of  chromium, 
being  very  insoluble,  are  highly  valued  and  some  of 
these  are  used  in  the  printing  of  the  United  States 
paper  money. 

Chromyl  chlorid,  CrOjClj,  a  red,  fuming  liquid, 
is  obtained  by  distilling  a  mixture  of  potassium 
dichromate  and  sodium  chlorid  with  sulfuric  acid. 

Chromic  chlorid,  Cr2Clg,  is  obtained  by  acting 
with  chlorin  on  a  heated  mixture  of  chromic  oxid  and 
carbon. 

Toxicology. — Chromium  compounds,  especially 
the  dichromate  of  potassium,  are  irritant  poisons 
and  may  produce  either  acute  or  chronic  poisoning. 
Emetics  should  be  promptly  administered  followed 
by  magnesium  carbonate  and  demulcent  drinks-. 

Tests. — Soluble  chromium  compounds  may  be 
detected  jjy  the  greenish  precipitate  formed  with 
ammonia,  or  by  the  solutions  of  soluble  lead  salts 
which  produce  the  yellow  chromate  of  lead.  The 
insoluble  salts  may  be  recognized  by  the  borax  bead 
which,  in  the  oxidizing  flame,  is  reddish  when  hot, 
yellowish-green  when  cold,  and  in  the  reducing  flame 
it  is  green. 


CHAPTER  XIV. 
COBALT,  NICKEL,  MANGANESE,  ZINC. 

As  already  stated,  these  metals  c()ni])nse  the  second 
division  of  the  ammonium  sultid  group.  They  are 
precipitated  by  ammonium  sulfid,  in  the  presence 
of  ammonia  water  and  ammonium  chlorid,  as  sul- 
fids  and  separated  as  such.  The  ammonium  chlorid 
plays  the  part  of  a  solvent  for  the  metals  of  the 
later  groups  and  prevents  their  precipitation. 

The  first  two  metals,  cobalt  and  nickel,  are  of 
but  little  value  pharmaceutically  and  have  no 
official  preparations.  In  chemistry,  the  arts  and 
manufactures,  howeverj  they  are  more  important. 
Manganese  and  zinc,  on  the  other  hand,  are  of  much 
more  importance,  both  pharmaceutically  and  in  the 
arts. 

COBALT,  Co.,  59.5.     Sp.  gr.,  8.9. 

Occurs  native  only  in  meteorites.  Its  most  im- 
portant ores  are  spiess-cobalt,  or  "smaltine,"  CoAsj; 
cobalt  glance,  or  "cobaltite,"  CoAs^CoSo,  and  the 
arsenical  sulfid,  CoAsS. 

The  metal  is  obtained  by  reduction  of  the  chlorid 
with  hydrogen,  but  the  processes  emploved  are  com- 
plicated. 

Cobalt  is  a  lustrous-white,  tenacious  metal,  malle- 
able and,  when  heated,  quite  ductile.  It  melts 
with  difficulty.  It  becomes  magnetic  and  holds  this 
125 


126  PHARMACEUTIC    CHKMISTRY. 

])n)])LTty  even  when  heated  to  redness.  It  is  unal- 
tered in  the  air  excej)!  in  very  fine  powdered  form. 
It  forms  three  oxids:  cobaltous  oxid,  CoO,  a 
drab-colored  powder,  obtained  by  reducing  the  ses- 
quioxid;  cobaltic  oxid,  CojOg,  and  cobalto-cobaltic 
oxid,  C03O4,  also  several  others  of  less  importance. 
It  also  forms  cobaltic  hydroxid,  Co(OH)2,  when  pre- 
cipitated with  the  caustic  alkalis,  cobaltous  chlorid, 
C0CI2;  cobaltous  sulfate,  CoSO^  +  7H2O,  etc. 

Cobalt  also  forms  a  large  number  of  complex 
ammoniacal  cobalt  compounds,  which  will  be  men- 
tioned later. 

When  cobalt  compounds  are  fused  with  borax, 
a  clear,  blue,  glassy  bead  is  produced,  and  a  similar 
blue  is  imparted  in  the  same  way  to  ordinary  blue 
glass,  due  to  the  formation  of  silicates  of  cobalt.  This 
cobalt  silicate,  finely  ground,  forms  a  pigment  known 
as  "smalt,"  and  is  employed  in  decorative  arts. 

Cobalt  chlorid  in  solution  forms  "sympathetic 
inks" — invisible  until  heated.  With  NaOH,  the 
salts  of  cobalt  yield  a  blue  precipitate,  which  on 
boiling  is  converted  into  the  hydroxid. 

NICKEL,  Ni,  58.7.     Sp.  gr.,  8.9. 

The  i)roperties  of  nickel  are  so  similar  to  coljalt 
as  to  require  no  special  discussion.  The  principal 
ores  of  nickel  are  niccolite,  NijAsj,  and  nickel  glance, 
NiAsjNiSa-  The  metal  is  obtained  by  reducing  the 
oxid  with  carbon  or  by  hydrolysis.  The  compounds 
of  nickel  correspond  to  those  of  cobalt.  Nickclous 
oxid,  NiO;  chlorid,  NiCl.,;  sulfid,  NiS.  Nickel 
linds  much  use  in  alloys  and  electroplating. 


MANGANESE. 


127 


Nickel  imparts  a  red-brown  color  to  the  borax 
bead  in  the  oxidizing  flame,  and  gray  opaque  in  the 
reducing  flame.  The  presence  of  cobalt  masks 
these  colors  entirely  and  must  be  removed  before  a 
flame-test  for  nickel  is  made. 

MANGANESE,  Mn,  55.     Sp.  gr.,  7.2 

Never  found  native  in  the  metallic  state,  but  it  is 
widely  distributed  in  combination  with  oxygen  as 
pyrolusite,  Mn02;  hraunite,  yin^O^;  haiismannite, 
Mn304;  also  as  manganUe,  Mn203,H20,  and  as  spar, 
MnC03.  The  metal  may  be  obtained  by  reducing 
its  ores  with  charcoal. 

Manganese  is  a  hard,  steel-gray,  Ijrittle  metal, 
oxidizes  readily  in  the  air,  and  is  readily  acted  upon 
by  hydrochloric  and  sulfuric  acids.  The  metal 
finds  but  little  use  in  the  free  state,  but  as  an  alloy 
with  iron,  spiegeleisen  and  jerromanganese,  it  is 
used  in  steel  making. 

Manganese  combines  the  properties  of  both  a 
metal  and  an  acid.  Manganese  forms  "ous"  com- 
pounds, MnR2;  "ic"  Mn2Re,  and  salts  of  manganic 
acid,  H2Mn04,  called  manganates.  It  forms  the 
usual  series  of  salts  of  all  three  types. 

The  precipitated  black  oxid  (mangani  dioxidum 
precipitatum  U.  S.  P.),  MnO.,  should  be  at  least  80% 
pure. 

Description.— Hea.\y  black  powder,  odorless,  per- 
manent. Used  as  a  catalytic  to  produce  oxygen 
from  potassium  chlorate,  and,  heated  with  sulfuric 
acid,  loses  its  own  oxygen  and  forms  manganous 
sulfate,  commonly  known  as  pink  vitriol. 


128  PHARMACKUTIC    CHEMISTRY 

Mauganese  hypophosphite  (mangani  livpoj)hos- 
phis  U.  S.  P.),  Mn(PH202)  +H2O,  is  official. 

Description. — Pinkish-white  crystalHne  powder, 
odorless  and  tasteless,  soluble  in  6.5  parts  water; 
at  least  79%  pure.  The  hypophosphite  is  used  as  a 
tonic  and  enters  into  the  syrup  hypojjhosphites 
compound. 

Manganese  sulfate  (mangani  sulphas  U.  S.  P.), 
MnSO^  +  4H2C).  Manganese  sulfate.  Pink  vitriol. 
Purity,  99.5%. 

Preparation. — PVom  the  dioxid  with  sulfuric  acid; 

Reaction: 

2Mn02  +  2H2SO,  =  2MnSO,  +  2H2O  +  O2. 

manganous 
sulfate 

Description. — Transparent,  pale,  rose-colored  crys- 
tals, odorless,  but  bitter  astringent  in  taste,  readily 
soluble,  used  as  a  hematinic. 

The  derii'atives  of  manganic  acid,  are  analogous 
to  salts  of  sulfuric  acid,  the  manganese  acting  as 
a  hexad.  The  manganates  are  not  permanent, 
but  are  readily  convertible  into  the  permanganates. 
The  most  common  permanganate  is  the  salt  of  potas- 
sium. 

Potassium  permanganate  (potassii  permanganas 
U.  S.  P.),  KMnO^,  is  prepared  from  the  dioxid. 
The  reaction  takes  place  in  two  stages: 

(i)  6KOH-t-KC103  +  3Mn02  ^  sMInO,   -|- 

\r  0\     1     ~,\i  r\  manganese  potassium 

KV^l   i-  3112^^-  dioxid  manganale 

The  green  manganate  of  potash,  KjMnO,, is  then 
changed  to    permanganate    b\-  extracting  the  mass 


ZINC  129 

with  boiling  water,  cooling  and  passing  chlorin  into 
it: 

(2)    2K2MnO,    +    CL,  =  2KCI  +  2KMnO,. 

potassium 
permanganate 

The  solution  is  then  crystallized.  The  perman- 
ganate forms  dark-red,  almost  black,  rhombic 
prisms.  It  has  very  strong  oxidizing  properties, 
and  finds  much  use  in  this  capacity  as  a  disinfectant, 
deodorant  and  antiseptic  solution.  It  decomposes 
with  organic  substances;  pills  of  the  permanganate 
are  best  made  by  triturating  the  salt  with  kaolin 
and  massing  with  petrolatum. 

ZINC,  Zincum,  Zn,  65.     Sp.  gr.,  6.8-7.2. 

This  element  always  occurs  in  combination. 
Its  compounds  are  only  fairly  abundant.  The 
most  important  zinc  ores  are  the  carbonate,  a//- 
(//^//;/f,  ZnCO.,;  the  sulfid,  or  zinc  blende,  sphalerite, 
ZnS,  and  red-zinc  ore,  ZnO,  found  in  New  Jersey, 
as  is  also  jranklinite,  (ZnFe)OI''e203. 

The  ])r<)cess  of  extraction  usually  consists  of  two 
ste])s:  (i)  roasting  to  convert  into  an  oxid,  and  (2) 
mixing  this  with  carbon  and  igniting  in  earthenware 
retorts,  and  thus  reducing  the  oxid.  The  i)rocesses 
vary  according  to  the  nature  of  the  ores.  The  crude 
metal  so  obtained  is  known  as  "spelter,"  and  is 
contaminated  with  iron,  lead,  arsenic,  cadmium,  etc. 
It  is  purified  from  these  by  a  second  distillation. 
Arsenic  is  a  commonly  found  impurity,  even  in  the 
better  grades. 

Zinc  is  a  bluish-white,  highly  crystalline  and  brittle 
metal  which  can  be  pulverized.  {Zinc-dust  is  so 
9 


130  PHARMACKUTIC    CHEMISTRY. 

prepared.)  \N'hen  heated  l)et\veen  150° and  200°  C, 
zinc  is  malleable  and  ductile,  and  at  still  higher 
temperatures  it  again  becomes  brittle.  Zinc  fuses 
at  412°  C,  and  distills  at  940°  C.  It  dissolves 
readily  in  dilute  acids  forming  corresjxjnding  salts 
and  liberating  the  hydrogen  of  the  acids.  It  is  also 
soluble  in  alkalin  hydro.xids,  forming  Zincates. 

Since  it  is  not  affected  by  the  air,  it  finds  much  use 
as  an  outside  coating,  such  as  the  "galvanizing"  of 
iron,  etc. 

Zinc  is  official  (Zincum)  and  is  required  to  be  at 
least  99%  pure  and  free  from  arsenic. 

Granulated  zinc  is  made  by  pouring  molten  zinc 
into  water. 

The  zinc  allovs  with  copper,  such  as  brass,  are 
valued  and  are  much  used.  It  also  alloys  with  tin, 
copper  and  antimony  in  all  proportions,  but  with 
lead  and  bismuth  in  definite  proportions  only. 

German  silver  is  an  alloy  of  copper,  zinc  and  nickel. 

The  present  Pharmacopoeia  recognizes  the  follow- 
.  ing  zinc  compjounds: 

Zinc  acetate  (Zinci  acetas  U.  S.  P.),  Zn,  (C.HjO,), 
— 2H2O;  99.5%   pure. 

Zinc  hromid  (zinci  bromidum),  ZnBr.,;  97',,   pure. 

Zinc  carbonate  (zinci  carbonas  precipitatus), 
which  should  yield  not  less  than  72%  of  zinc  oxid. 

Zinc  chlorid  (zinci  chloridum),  ZnCU;  99.5%  pure. 

Zinc  iodid  (zinci  iodidum),  Zniz,  when  anhydrous, 
should  contain  not  less  than  98%  of  pure  zinc  iodid. 

ZiJic  oxid  (zinci  oxidum),  ZnO;  at  least  99-5^V 
pure. 


zINC.  131 

Zinc  phenoJsidjonate  (zinci  phenolsulphonas), 
Zn(C6H5SOj2,8H20;  the  uneffloresced  crystals 
should  contain  at  least  99.5%  of  the  pure  salt. 

Zinc  stearate  (zinci  stearas),  Zn(Ci8H3502)2- 

Zinc  sulfate  (zinci  sulphas),  ZnSO^  +  yHjO; 
99.5%  pure,  "white  vitriol." 

Zinc  valerate  (zinci  valeras),  Zn(C5H902)2  +  2H20; 
99%  pure. 

Of  the  above  zinc  salts,  all  are  soluble  in  water  and 
poisonous,  except  the  carbonate,  stearate  and  oxid. 
The  last  of  these  three  finds  much  use  in  paints  as 
a  pigment,  together  with  lead  carbonate,  to  give  the 
latter  greater  lasting  qualities. 

The  zinc  salts  are  prepared  by  acting  upon  the 
metal  or  its  oxid  or  carbonate  uith  the  corresponding 
acid.  The  action  of  the  zinc  salts  is  due  largely  to 
the  acid  present  in  the  compound  and  they  are  there- 
fore astringent,  antiseptic  or  disinfectant,  as  the  case 
may  be. 

Toxicology. — All  soluble  zinc  salts,  as  stated,  are 
poisonous.  The  chlorid  is  used  by  tinsmiths,  also 
in  embalming  and  as  "Burnett's  disinfecting 
fluid."  In  all  these  it  acts  as  corrosive.  The  best 
zinc  antidotes  are  soap,  milk  and  soluble  alkali  car- 
bonates, or  substances  containing  tannin,  such  as  tea 
or  coffee. 

Tests. — With  alkalin  carbonates  or  hydroxids, 
zinc  compounds  in  solution  give  a  white  precipitate 
soluble  in  excess  of  the  reagent.  Potassium  ferro- 
cyanid  gives  a  yellowish-white  precipitate,  insoluble 
in  dilute  hydrochloric  acid. 


CHAPTER  XV. 

BARTOM,  STRONTIUM,  CALCIUM. 

THE  CARBONATE  GROUP. 

The  three  metals  of  this  group  possess  quite 
similar  properties.  They  form  insoluble  carbonates 
in  ammoniacal  solutions,  even  in  the  presence  of 
ammonium  chlorid,  which  is  present  here  to  prevent 
the  precipitation  of  magnesium  at  the  same  time. 
They  form  insoluble  carbonates,  and  hence  the  name 
"carbonate  group."  Magnesium,  through  the  inter- 
vention of  ammonium  chlorid,  is  placed  in  the  next 
group,  although  it  has  many  properties  in  accord 
with  the  members  of  this  group. 

The  members  of  the  carbonate  group,  with  the  ex- 
ception of  calcium,  are  not  of  interest  pharmaceuti- 
callv,  for  there  are  no  official  salts  of  barium,  since 
barium  dioxid  was  dropped,  and  strontium  has  but 
three  recognized  salts.  There  are,  however,  ten  com- 
pounds of  calcium  official  and  many  more  commonly 
used. 

BARIUM,  Ba,  137.2.  Sp.  gr.,  4. 

Barium  docs  not  occur  native,  and  the  metal  is  so 
difficult  to  isolate  that  some  doubt  exists  a^  to 
whether  strictly  pure  barium  has  ever  been  i)roduce(l. 

Its  most  al)undant  natural  compounds  are  heavy 
spar,  BaSO^,  a.m\  icithcrite,  BaCO.,. 
132 


STRONTIUM.  133 

Barium  forms  two  oxids,  BaO  and  BaOj. 

Barium  dioxid,  BaUj,  is  a  grayish-white  powder, 
decomposed  by  dilute  acids,  and  this  property  has 
made  the  salt  valuable  in  the  preparation  of  solutions 
of  hydrogen  dioxid;  thus: 

3Ba03  +  2H3PO,  =  3H3O2  +  BagiPO,)^. 

hydrogen 
dioxid 

Barium  nitrate,  Ba(N03)2,  finds  use  only  as  a 
reagent  and  for  producing  "green  fires"  (Bengal 
lights). 

Barium  sulfid,  BaS,  is  prepared  by  reducing  the 
sulfate  liv  heating  with  coal  dust.  The  salt  is 
soluble  in  water  and  used  as  depilatory. 

Barium  chlorid,  BaCl2,  and  barium  carbonate, 
BaCOg,  find  use  as  chemical  reagents  only. 

Toxicology. — SoliiUe  salts  of  barium  are  poisonous, 
though  but  few  cases  of  poisoning  with  barium  ever 
occur.  Any  soluble  sulfate,  such  as  sodium  or 
magnesium  sulfate,  when  given,  form  with  barium, 
insoluble  sulfates,  w^hich  should  be  removed  with 
emetics. 

Tests. — Barium  salts  are  readily  precipitated 
from  their  solutions  with  soluble  carbonates  or 
sulfates,  and  the  sulfate  so  formed  is  insoluble 
in  acids.  Chromates  also  produce  an  insoluble, 
primrose-yellow  barium  chromate;  distinction  from 
calcium  and  strontium,  which  form  soluble  chromates. 

STRONTIUM,  Sr,  87.3. 

The  principal  minerals  of  strontium  SLvestronti  initc, 
SrCOg,  and  celestite,  SrSO^.  These  ores  are  found 
but  sparingly.     Strontium   is  found   in  verv   small 


134 


PHAKMACKUXrC    CHEMISTRY. 


(juantities  in  gvpsuni,  some  limestones  and  mineral 
waters. 

Description. — Strontium  is  a  yellow,  lustrous 
metal,  and  resembles  barium  and  calcium  in  most 
properties.  Strontium  compounds  impart  a  red 
color  to  the  flame,  and  the  nitrate  is  much  used  in 
pyrotechny  as  the  principal  constituent  of  "red  fires." 

Strontium  salts  are  not  considered  as  poisonous 
except  in  large  quantities.  As  stated,  there  are 
but  three  salts  officially  recognized. 

Strontium  bromid  (strontii  bromidum  U.  S.  P.), 
SrBr2,6H20.  Purity,  97%.  Description:  Colorless, 
transparent  crystals,  very  deliquescent,  soluble  in 
one  part  of  water.  Used  in  medicine  as  a  sedative 
nervine. 

Strontium  iodid  (strontii  iodidum  U.  S.  P.),  Sri, 
+  6H2O,  should  be  at  least  98%  pure. 

Description. — Colorless,  transparent  plates;  deli- 
quescent and  not  permanent  in  the  air.  Soluble 
in  0.5  part  of  water.     Used  as  an  alterative. 

Strontium  salicylate  (strontii  salicylas  U.  S.  P.), 
SrCC^HsOg),  +  2H,0.  Purity,  98.5%.  White,  crys- 
talline powder,  soluble  in  18  parts  of  water.  Used 
medicinally  as  an  antirheumatic  and  antiseptic. 

All  the  strontium  salts  are  prepared  by  acting  upon 
the  carbonate  or  hydroxid  with  the  respective  acid 
solution. 

Tests. — Strontium  may  be  detected  by  the  crimson 
color  imparted  to  the  flame. 

With  sulfuric  acid,  strontium  salts  form  insoluble 
sulfates. 


CALCIUM.  135 

With  soluble  carbonates  or  t)xalates,  strontium 
salts  give  insoluljle  precipitates. 

The  precipitated  sulfate  is  insoluble  in  solution 
of  ammonium  sulfate  (distinction  from  calcium). 

CALCIUM,  Ca,  40.     Sp.  gr.,  1.6. 

Calcium  does  not  occur  free,  but  is  very  widely 
distributed  in  its  compounds.  The  carbonate, 
CaCOg,  in  limestone,  marble  and  chalk,  the  sulfate, 
CaSO^,  as  gypsum  and  alabaster,  and  the  phosphate, 
CaH^(P04)2,  silicate,  CaSiOg,  and  fluorid,  CaFa, 
are  most  widely  distributed  minerals.  Some  of 
these  compounds  occur  in  most  natural  waters  and 
soils  and  also  in  vegetable  and  animal  tissues. 
Bones  consist  largely  of  calcium  phosphate.  The 
element  was  first  isolated  by  Davy  (1808),  the 
most  common  means  of  separation  now  being 
through  the  electrolysis  of  the  fused  chlorid. 

Properties. — Calcium  is  a  pale,  brass-yellow 
colored  metal,  hard  but  malleable;  acted  on  easily 
by  moist  air,  burns  readily  when  heated  in  air,  and 
decomposes  water. 

Compounds. — The  compounds  of  calcium  are 
numerous  and  of  much  value  commercially  as  well  as 
pharmaceutically  and  medicinally.  Ten  salts  or 
compounds  are  recognized  in  the  Pharmacopeia. 

Calcium  bromid  (calcii  bromidum  U.  S.  P.),  CaBrj; 
97%  pure. 

Preparation. — From  the  carbonate  with  hydro- 
bromic  acid.     Reaction: 

CaCO,  +  2HBr  =  CaBr,  +  H,0  +  Co^. 


136  I'lIAKMACKl  TK:    CHExMISTRY. 

Very  soluble.  All  the  other  salts  of  ralriiiin  maybe 
prepared  in  a  similar  icay. 

Calcium  hypophosphite  (caleii  hypophosphis, 
U.  S.  P.),  Ca(PH,()2).;  98%  pure.  This  is  prepared 
by  warming  calcium  hydroxid  with  ])hosph{)rus  and 
water. 

In  preparing  this  salt  great  care  must  be  used,  as 
phosphin,  PH,,  a  highly  explosive  gas  is  formed, 
and  good  draughts  are  necessary  to  carry  it  off. 
The  temperature  employed  should  not  exceed  85°  C. 
4P2  +  3Ca(OH)2  +  6H3O  =  3Ca(H,PO.>\  +  2PH,. 

calcium 
hypophosphite 

Quicklime  (calx  U.  S.  P.),  CaO.  Calcium  oxid. 
Lime. 

Description. — Hard,  white  or  gray  masses;  soluble 
in  760  parts'  of  water.  In  air  it  slowly  absor])s 
moisture  and  falls  to  a  gray  powder  (air-slaked  lime, 
CaOH).,).  With  water  this  change  takes  place 
rapidly. 

Quicklime  is  manufactured  from  limestone — 
native  calcium  carbonate,  CaCC), — by  burning  in 
kilns  (narrow  furnaces,  usually  of  brickV  to  remove 
carbon  dioxid.     Thus: 

CaCOa  =  CaC)  +  CO,. 

limestone  lime 

or  marble 

Lime  is  noncombustible,  and  when  heated  in  the 
oxyhydrogen  flame  it  emits  a  brilliant  light  known  as 
the  "lime  light."  It  is  much  used  as  a  drying  agent 
on  account  of  its  affinity  for  water.  When  slaked 
as  described,  it  becomes  a  hydroxid  which  is  slightly 
soluble,   and   solutions  of   this   arc   known   as   lime 


MMK.  137 

wafer  (li(|U(>i-  calcis  U.  S.  P.)  which  should  contain  at 
least  0.14%  of  the  hydroxid.  The  hydroxid,  citrate 
and  oxalate  of  calcium  are  more  soluble  in  cold  than 
in  hot  water.  "Milk  of  lime"  is  a  pasty  mass  of 
calcium  hydroxid  with  water,  made  by  slaking  lime, 
the  lime  being  in  excess.  Lime  also  enters  into 
building  mortars  where  its  cementing  property  is 
due  to  the  absorption  of  carbon  dioxid  from  the  air 
whereby  the  calcium  carbonate  forms. 

Chlorinated  Lime  (calx "  chlorinata  U.  S.  P.), 
Ca(OCl)Cl.  lileaching  powder,  bleach,  "chloride 
of  lime."  It  should,  when  assayed,  yield  not  less 
than  30%  of  available  chlorin.  It  is  prepared  bv 
the  action  of  chlorin  on  slaked  lime.  When  treated 
with  water,  the  following  reaction  occurs: 

2Ca(0Cl)Cl  =  CaCls  +  Ca(0Cl)2. 
When  treated  with  acids,  chlorin  is  generated: 

Ca(OCl)Cl  +  H,SO,  =  CaSo,  +  H^O  +  CU. 
Chlorinated  lime  is  used  as  a  disinfectant,  deodorant 
and  as  a  bleaching  agent.  It  enters  into  the  solution 
of  chlorinated  soda,  commonly  called  "  Labarraques" 
(liquor  sodae  chlorinatae)  which  should  contain  at 
least  2.4%  of  available  chlorin. 

Suljurated  lime  (calx  sulphurata  U.  S.  P.),  suf- 
furated  lime,  crude  calcium  sulfid,  is  a  mixture  con- 
taining at  least  60%  calcium  sulfid,  with  sulfate 
and  carbon.  Made  by  heating  together  70  parts  of 
dried  calcium  sulfate,  10  parts  of  charcoal  and  2 
parts  of  starch  to  redness  until  the  mass  loses  its 
black  color.  Then  it  is  pulverized  and  should  be 
preserved  tightly  stoppered. 


138  PHARMACKITIC    CHEMISTRY. 

Calcium  carbid,  ('aC.,  unoftuiul,  is  prepared  in 
an  electric  furnace  from  coal  tar  and  lime.  It 
decomposes  in  contact  with  water,  furnisliino;  acety- 
lene gas,  according  to  the  equation: 

CaC,  +  2H.,0  =    QH^^  +  Ca(()H).,. 

acetylene 

Precipitated  calcium  carbonate  (calcii  carbonas 
precipitatus  U.  S.  P.),  CaCOg,  ])recipitated  chalk; 
purity  gg^;  :  The  salt  is  made  by  precij)itating 
calcium  chlorid  with  a  soluble  carbonate,  as  sodium: 

CaClj  +  Na^COj  =  CaCOg  +  2NaCl. 
This  is  a  purer  salt  than  prepared  chalk  (creta  pre- 
parata  U.  S.  P.),  CaCO, — a  white  or  gray  powder  or 
moulded  conical  drops,  made  by  elutriation.  The 
prepared  chalk  is  less  crystalline  and  smoother 
than  precipitated  chalk,  and  hence  is  directed  in 
preparations  for  internal  administration. 

"Paris  white"  and  "whiting"  are  synonyms  for 
the  impure  prepared  chalk,  l)oth  arc  used  in  polishing 
mixtures,  etc. 

Calcium  chlorid  (calcii  cliloridum  U.  S.  P.),  CaCU; 
99%  pure. 

Description. — Anhydrous,  white,  fused  masses; 
very  deliquescent,  readily  soluble.  Its  greatest 
value  is  as  a  drying  agent,  due  to  its  great  atTmity 
for  water,  which  it  will  absorb  from  gases  or  liquids. 

Precipitated  calcium  phosphate  (calcii  phospl  as 
l)recipitatus,  U.  S.  P.),  Ca.,(P()^y^.  Bone  phosphate, 
normal  calcium  ortho])hosphatc;  purity,  99%.  A 
permanent,  white,  insoluble  powder.  The  salt 
occurs  in  the  phosphate  rock  of  I'Morida  and  South 


CALCIUM    COMPOUNDS.  139 

Carolina,  in  which  it  is  sometimes  found  u])  to  90%. 
The  "precipitated  phosphate  "  is  made  by  adding 
calcium  chlorid  and  ammonium  hydroxid  to  phos- 
phate, known  as  "white  rouge." 

A  number  of  phosphates  are  formed  with  calcium, 
such  as  tricalcic  phosphate,  bone  phosphate,  dical- 
cium  phosphate,  Cx^U^iFO^)^,  and  monocalcium 
phosphate,  CaH4(POj2  "superphosphate."  The 
rock  phosphate  is  used  extensively  as  a  valuable 
fertilizer. 

Calcium  sulfate,  CaS04  +  2H2O.  Crystalline, 
sparingly  soluble,  called  gypsum,  selenite  and 
"terra  alba."  Heated  to  120°  C,  it  gives  up  its 
water,  becomes  an  opaque  mass,  which,  when  ground, 
constitutes  the  official  "plaster  of  Paris"  (calcii 
sulfas  exsiccatus,  U.  S.  P.),  CaS04,  "dried  gypsum." 
The  "plaster  of  Paris"  still  contains  about  5%  of 
water.  When  mixed  with  water,  it  reabsorbs  two 
molecules  of  it  and  hardens  to  a  stone-like  mass. 
Upon  this  property  depends  the  value  of  plaster  of 
Paris  in  preparing  surgical  dressings,  moulds,  etc. 

Calcium  salts  are  not  poisonous  and,  in  fact,  are 
found  normally  present  in  every  part  of  the  human 
body,  in  tissues,  fluids  of  the  body,  etc.,  being  most 
abundant  in  the  bones  and  teeth — bones  containing 
about  55%  and  teeth  about  72%  of  calcium  salts. 

Tests.  Calcium  may  be  detected  in  solution  by 
its  insoluble  carbonates,  sulfates  and  especially  its 
oxalate  precipitates,  which  are  formed  with  the. 
soluble  salts  of  the  corresponding  acid. 

With  Bunsen  flame  it  gives  a  brick-red  coloration. 


CHAPTER  XVI. 

THE  ALKALI-METAL  GROUP. 

Lithium,       7  Rubidium,     85 

Sodium,      23  Cesium,        133 

Potassium,  39  Ammonium,  18 

We  have  no  general  reagent  for  the  metals  of  this 
group.  Each  member  is  separated  or  detected  in- 
dividually. 

Their  grouping  together  is  due  to  a  number  of 
characteristics,  which  they  possess  in  conimon. 
Thus: 

All  have  a  low  specilic  gravity;  are  monatomic; 
soft  and  easily  fusible;  have  great  afiinity  for  o.xvgen 
and  decompose  water,  forming  hydroxids  which  dis- 
solve in  excess  of  water.  These  hydroxids  turn  red 
litmus  blue,  neutralize  acids,  saponify  fats  and,  if 
strongly  concentrated,  are  caustic  .to  the  point  of 
eschar.  These  properties,  characteristic  of  alkalis, 
give  the  name  of  "alkali  metals"  to  the  mcml)ers  of 
this  grouj).  Their  great  affinity  tor  oxygen  causes 
them  to  oxidize  in  the  air,  to  tarnish  immediately  and 
even  to  take  fire,  due  to  the  heat  produced  by  the 
ra])id  oxidation.  They  are,  therefore,  kept  beneath  a 
mineral  oil,  free  from  oxygen,  to  prevent  ra])id  oxida- 
tion. 

Lithium,  .sodium  and  jxttassium  were  discovcreil  in 
140 


LITHIUM.  141 

1807-1808  by  Sir  Humphrey  Davy,  and  cesium  and 
rubidium  by  Kirchoff  and  Bunsen  in  1860-1861. 

The  relation  between  the  atomic  weights  is  an  in- 
teresting point.  There  is  a  difference  of  16  in  the 
atomic  weight  of  lithium  and  sodium;  the  same  be- 
tween sodium  and  potassium;  practically  three  times 
sixteen  between  potassium  and  rubidium  and  between 
rubidium  and  cesium.  This  seems  to  show  them  to 
lie  in  an  homologous  series,  with  two  undiscovered 
metals  belonging  in  the  spaces  on  each  side  of 
rubidium.  These  metals  form  many  salts,  but  only 
one  chlorid,  bromid  and  iodid.  As  a  general  state- 
ment, it  may  be  said  that  the  salts  of  alkali  metals 
are  white,  crystalline  compounds,  soluble,  odorless, 
characteristic  in  taste  and  permanent. 

LITHIUM,  Li,  7.     Sp.  gr.,  0.589. 

Occurrence. — Lithium  occurs  widely  distributed,  but 
in  very  small  quantities,  as  in  mineral  springs,  in 
plants,  especially  in  tobacco  and  the  beet.  It  is 
usually  separated  from  its  chlorid  by  electrolysis. 

Properties. — A  silver-white  matal,  fusible  at  180°  C, 
burns  with  an  intense  red  flame.  It  is  the  lightest 
metal  of  the  solid  elements. 

Compounds. — The  salts  of  lithium  so  closely  re- 
semble those  of  sodium  as  to  require  no  separate  dis- 
cussion. 

Those  recf)gnized  officially  are: 

Lithium  bromid  (lithii  bromidum  U.  S.P.),  LiBr.; 
purity,  97%. 

Used  as  a  sedative  nervine. 

Lithium  carbonate  (lithii carbonas  U.  S.  P.),Li2C03; 


142  I'flARMACEUTlC    CHEMISTRY. 

purity,  98.5^^-      Made  according  to  the  following  re- 
action: 

LijSO.  +  lNHj.COg  =  Li,C03  +  (NH,)2SO,. 

lithium^ 
carbonate. 

Used  as  an  alkalin  diuretic. 

Lithium  citrate  (lithii  citrus  U.  S.  P.),  Li-jC^H^O^ 
-(-4H2O;  purity,  98. s*^'^.  Preparation  from  the  car- 
bonate: 

sLi^CO,,  +  2H3C6H5O7  =  2Li3C6H507  + 
3H,0  +  3CO3. 
Used  as  a  diuretic.  This  salt  forms  with  uric  acid 
a  salt,  which  is  the  most  soluble  of  all  its  com- 
pounds; hence  the  use  of  lithium  in  uric-acid 
j)oisoning.'  It  enters  into  (lithii  citras  effervescens, 
5%)  the  effervescent  citrate. 

Lithium  salicylate  (lithii  salicylas  U.  S.  P.), 
LiC^H^O^;  purity,  98.5'^{.  Used  as  an  antirheu- 
matic. 

Lithium  bciizoate,  (lithii  benzoas  U.  S.  P.), 
LiC7H502;  purity,  98. 5^;, .  The  salt  is  used  as  an 
intestinal  antiseptic.  •  As  may  be  readily  seen,  all  the 
salts  of  lithium  may  be  prepared  by  the  action  of  the 
res])ectivc  acid  upon  lithium  carbonate.  The  phys- 
ical characteristics  of  the  lithium  salts  are  so  similar 
to  those  of  sodium  that  in  general  the  descrij)tion  oi 
the  corresponding  sodium  salt  will  apply  to  lithium 
as  well.     Sec  later  description  under  Sodium. 

POTASSIUM,  Kalium;     K,  39.    Sp.  gr.,  0.865. 

(^Ciiinrucr.-  Widely  distributed  in  rocks  and 
minerals,  particularly  as  syh-itc,  KCl,  and  carnallitc, 
KCl,  MgCU,6H/);  found  in  the  mines  of  Stassfurt, 


POTASSIUM.  143 

Germany,  which  are  the  principal  source.  Also 
found  in  plant  ash,  in  argols  (crude  potassium  tar- 
trate), and  in  niter  beds  Calcutta  niter,  KNO.^. 

Preparation. — The  metal  is  obtained  by  reduction 
of  its  carbonate  by  means  of  carbon  and  high  heat 
in  an  iron  retort  and  subsequent  redistillation. 

Properties. — It  is  a  silver-white,  lustrous  metal, 
soft  at  ordinary  temperature,  brittle  at  0°  C,  fusing  at 
62°  C.  It  distills  at  a  red  heat.  Potassium  has  great 
afilinity  for  oxygen,  and  tarnishes  immediately  when 
exposed  to  the  air,  and  frequently  ignites.  It  burns 
with  a  peculiar  grayish-purple  flame.  It  decomposes 
water,  liberating  hydrogen  gas.  Must  be  preserved 
under  a  hydrocarbon  oil,  as  kerosene. 

Compounds. — The  salts  of  potassium  arc  very 
numerous  and  very  common,  many  quite  similar  to 
the  corresponding  sodium  salt,  which  can  be  seen  for 
comparison.  There  are  eighteen  compounds  of 
potassium  recognized  in  the  U.  S.  P. 

Potassium  hydro.xid  (potassii  hydroxidum  U.  S.P.), 
KOH.  (Potassa  U.  S.  P.  'go);  potassium  hydrate, 
caustic  potash.  Made  by  the  action  of  slaked  lime 
on  potassium  carbonate.  The  solution  is  decanted, 
evaporated  to  dryness,  fused  and  cast  into  moulds: 

K2CO3  +  CaCOlflj  =  2KOH  -f  CaCOg. 
Purity,  85%,  and  not  more  than  2%  of  other  inorganic 
substances,  with  the  exception  of  water.  White, 
hard  pencils,  very  soluble  in  water  and  in  alcohol. 
With  fats,  mixed  oils  and  resins  it  forms  soaps. 
Uses:  caustic  and  solvent.  Preparations:  liq.  potas- 
sii hydroxidi,  f/f,. 


144  PHARMACEUTIC    CHEMISTRY. 

Virnita  lime  (polassa  cum  calce),  not  official. 
Made  by  fusing  together  equal  parts  of  KOH  and 
CaO. 

Potassium  acetate  (potassii  acetas),  KCjHjO,. 
Purity  98%.  A  white  powder  or  crystalline  masses, 
saline  taste;  very  deliquescent.  Made  by  decom- 
posing potassium  bicarbonate  with  acetic  acid,  filter- 
ing and  evaporating. 

KHCO3  +  CH3COOH  =  CH3COOK  +  CCX  +  H^O. 
Soluble  in  0.4  part  water,  2  parts  alcohol.  Precipi- 
tates strong  solutions  of  quinine  salts;  effervesces 
with  spirits  of  nitrous  ether.     Alkalin  diuretic. 

Potassium  bicarbonate  (potassii  bicarbonas), 
KHCO3.  Should  contain  not  less  than  99%  of  pure 
salt.  Colorless,  transparent  crystals  or  colorless, 
odorless,  granular  powder,  saline,  alkalin  taste. 
Prepared  by  ])assing  CO,  in  a  solution  of  a  carbonate, 
evaporating  and  crystallizing.  .Antacid.  Soluble  in 
3  parts  water,  almost  insoluble  in  alcohol. 

KX'()3  +  CO,  +  H,()  =  2KHCO3. 
Also  called  "saleratus''  or  "baking  salt." 

Potissinm  bitarlrate{\)ohx^A\  bitartras),  KHC,HjOg. 
Cream  of  tartar.  Purity,  99'','.  Colorless,  slightly 
opa(|ue  crystals  or  white,  gritty  ])owder.  Odorless, 
with  pleasant,  ;u  idulous  taste.  Made  by  purifying 
''argot,''  the  sediment  (le|)()siu-(l  during  fermenta- 
tion of  wine  in  barrels.  Soluble  in  200  parts  water, 
more  soluble  in  s  ilutions  of  borax  or  boric  acid, 
sparingly  soluble  in  alioliol.  \\'ilh  hydroxids  and 
carbonates  of  the  alkalis  it  forms  soluble  neutral 
salts.     Used  as  a  diuretic  and  cathartic.     As  cathar- 


POTASSIUM    COMPOUNDS.  I45 

tic,  it  is  often  prescribed  with  sulfur  and  adminis- 
tered with  molasses  and  water.  Impurity:  Calcium 
tartrate;  forming  white  precipitate  with  ammonium 
oxalate. 

Potassium  bromid  (potassii  bromidum  U.  S.  P.), 
KBr.  Purity,  97%.  Colorless,  in  cubical  crystals  or  a 
granular  powder.  Odorless,  possessing  a  strong 
saline  taste.  Made  by  treating  solution  of  i)otassium 
hydroxid  with  bromin,  evaporating  and  igniting 
with  charcoal.  In  the  reaction  both  the  bromid  and 
bromate  are  formed.  When  heated  with  charcoal 
and  starch,  the  bromate  is  deoxidized,  CO2  escaping. 
Thus: 

(i)  6K0H  +  3Br.,  =  sKBr  +  KBrO.,  +  3H3O. 
(2)  2KBr03+  3C  =  2KBr  +  6CO2. 

Potassium  carbonate  (potassii  carbonas  U.  S.  P.), 
K2CO3.  Sal  tartar,  pearlash.  Should  contain 
when  thoroughly  dried  not  less  than  98%  of  the  pure 
salt.  A  white,  granular  powder,  odorless,  strongly 
alkalin  taste,  very  deliquescent.  Made  by  purifying 
common  pearlash  by  dissolving  it  in  cold  water, 
filtering,  evaporating  and  granulating.  Carbonates 
are  decomposed  by  acids,  excepting  hydrocyanic. 
Both  potassium  and  sodium  carbonates  precipitate 
salt  solutions  of  nearly  all  other  common  metals. 
Free  alkaloids  are  precipitated  from  their  aqueous 
salt  solution  by  the  carbonates. 

Lye,  potash  and  "pearlash"  are  produced  when 
ashes  from  burnt  wood  are  lixiviated  or  "leached" 
(percolated)  with  water.  The  percolate  is  evapo- 
rated  in   iron   pots,   and   the   impure  carbonate  is 


146  I'HARMACKUTIC    (IlKMISTRY. 

called  "pearlash,"  "potash"  or  "lye".     SoluI)le  in  i 
part  of  water.     Poisonous. 

Potassium  chlorate  (potassii  chloras),  KCIO3. 
Kali  chloricum.  Purity,  99%.  Made  by  passing 
chlorin  gas  into  a  solution  of  potassium  hydroxid  and 
boiling,  according  to  the  following  reaction: 

6K0H  +  3CI2  =  5KCI  +  3H2O  +  KCIO3. 
Also  prepared  by  reacting  on  potassium  chlorid  with 
calcium  hypochlorite  solution.  Solul)le  in  16  parts 
water.  Chlorates  are  powerful  oxidizing  agents, 
incompatible  with  reducing  agents,  with  which  they 
explode  on  dry  trituration  or  heating.  When  tritur- 
ated with  organic  substances,  as  tannic  acid,  cork  or 
sugar,  or  with  inorganic  substances,  as  sulfur,  anti- 
mony sulfid,  phosphorus  or  other  easily  oxidizable 
substances,  it  conflagrates.  Description  :  Colorless, 
lustrous  prisms  or  plates  or  a  white  granular  i)-.)wdcr; 
odorless;  cooling  taste.  Used  as  antiseptic,  stimu- 
lant to  mucous  membrane.  Preparations:  Trociic, 
KCIO3  (0.15  gm.  in  each). 

Potassium  citrate  (potassii  citras  U.  S.  P.),  KaCy- 
H5O7  4-  H.^O.  Purity,  999;,.  Prepared  by  neutraliz- 
ing solutions  of  citric  acid  with  potassium  bicarbo- 
nate, evaporating  and  granulating: 
3KHC03  +  H3C«H507=K3C„H,()7  +  311,0  + 3C().,. 
Trans])arent  crystals  or  white,  granular  jjowder,  deli- 
(juescent,  odorless,  with  a  cooling  taste.  Soluble  in 
0.5  part  water,  sparingly  in  alcohol.  Incompati- 
ble with  le^d  and  silver  salts,  lime  water,  and 
quinine  solutions.     Used  as  alkalin  diuretic.     Prep- 


POTASSIUM    COMPOUNDS.  1 47 

arations:     Potassii   citras  effervescens,   20%;  liquor 
potassii  citras,  8%. 

In  the  Pharmacopoeia,  1880,  mistura  potassii  citra- 
tis  was  official,  known  as  "neutral  mixture."  This 
was  a  more  agreeable  preparation  to  the  taste,  made 
by  nearly  neutralizing  lemon-juice  with  potassium 
bicarbonate. 

Potassium  cyanid  (potassii  cyanidum  U.  S.  P.), 
KCN.  "Poisonous  prussiate  of  potash."  White, 
opaque,  amorphous  pieces  or  granular  powder;  odor- 
less when  dry;  deliquescent  in  air,  emitting  the  odor  of 
KCN.  Soluble  in  2  parts  water,  sparingly  in  alcohol. 
Potassium  dichromate  (potassii  dichromas  U.  S.P.), 
K2Cr207,  known  in  the  last  Pharmacopoeia  as  "  potassii 
bichromas."  Bichromate  of  potash.  Purity,  99%. 
Description:  Large,  orange-red,  transparent  prisms 
or  tabular  crystals,  odorless,  acid,  metallic  taste. 
Made  by  treating  potassium  chromate  with  sulfuric 
acid,  evaporating  and  crystallizing.     Thus: 

2K2CrO,  +  H,SO,  =  K2Cr20,  4-  K^SO,  +  HjO. 
A  powerful  oxidizing  agent,  almost  universally  in- 
compatible. Soluble  in  9  parts  water.  Insoluble  in 
alcohol.  Used  as  caustic  and  antiseptic  in  pills  or 
capsules,  with  kaolin  as  diluent  and  petrolatum  as 
excipient. 

Potassium  sodium  tartrate  (potassii  et  sodii  tartras 
U.  S.  P.),  KNaC^H.Og-f  4H2O.  Rochelle  salts, 
Seignettes  salts.  Colorless,  transparent  prisms  or 
white  powder.  Odorless,  cooling  taste,  efflorescent. 
Purity,  99%.  Made  by  treating  solution  of  potas- 
sium bitartrate  with  sodium  carbonate. 


148  PHARMACEUTIC    CHEMISTRY. 

2KHC,H,0„  +  Na,C03  =  2KNaC,H/)„  +  H,0 
+  CO,. 

Soluble  in  1.2  parts  water.  Insoluble  in  akoliol. 
Incompatible  with  nearly  all  acids.  Used  as  hydrc- 
gogue  purgative.  Preparations:  (Pulv.  Efferv. 
Comp.)  Seidlitz  powder. 

Potassium  jerrocyanid  (potassii  ferrocyanidum 
U.  S.  P.),  K.FeCNg  +  3H2O.  Yellow  prussiate  of 
potash.  Large,  soft,  transparent,  yellow,  four-sided 
crystals  or  prisms.  Odorless,  with  mild,  saline  taste. 
Slightly  efflorescent.  Purity,  99%.  Made  by  treat- 
ing nitrogenized  substances  (refuse  animal  matter, 
such  as  hair,  hoofs,  horns,  etc.)  with  crude  potash, 
with  which  impure  potassium  cyanid  is  formed. 
This  mass  is  lixiviated  and  treated  with  freshly 
precipitated  ferrous  carbonate,  with  which  the 
ferrocvanid  is  formed.     Thus: 

6KCN-f-FeC03  =  K,Fe(CN)6+K,C03. 
Soluble  in  4  parts  water;  insoluble  in  alcohol.  Used 
mainly  in  the  preparation  of  cyanids.  (Potassii 
ferricyanidum),  K3Fe(CN)e,  •  "Red  prussiate  of 
potash.  Not  oflicial.  Employed  as  reagent  for  the 
detection  of  ferrous  salts,  with  which  it  gives  blue 
precipitates. 

Potassium  Hypo  phosphite  (potassii  hypophosjyhis 
U.  S.  P.),  KPH-jO,.  Purity,  98%.  Should  be  pre- 
served in  well-stoppered  bottles.  White,  ojiacpie, 
hexagonal  plates  or  crystalline  masses  or  granular 
powder.  Description:  Odorless,  ]ningent,  saline 
taste,  very  dcliciuescent.  Made  l)y  i)recii)itating  cal- 
cium    hvp<)i)h<)Si)liitc     witli     ])(itas>iuni     cartionate, 


POTASSIUM    lODID.  149 

filtering,  evaporating  and  granulating  at  a  tempera- 
ture below  100°  C.  Above  this  degree  of  heat,  the 
salt  explodes.  Explosions  have  occurred  when  this 
salt  was  triturated  or  heated  with  nitrates,  chlorates 
or  other  oxidizable  substances.  Solubility:  0.5  part 
water,  7  of  alcohol.  Insoluble  in  ether.  Used  as 
expectorant  tonic.  Preparations:  Syr.  hypophos- 
phitum  (1.5%),  Syr.  hypophosphitum  comp.  (1.75%). 
CalPH^O,)^  +  K2CO3  =  2KPH2O2  +  CaCOg. 
Potassium  iodid  (potassii  iodidum  U.  S.  P.),  KI. 
Made  by  adding  iodin  to  hot  solution  of  KOH, 
evaporating  to  dryness,  mixing  with  charcoal  or 
starch,  heating  to  redness,  dissolving  in  water  and 
crystallizing. 

U)  3I2  +  6K0H  =  5KI  +  KIO3  +  3H2O. 

(2)  2KIO3  +  3C  =  2KI  +  3CO2. 
The  charcoal  or  starch  is  added  to  convert  the  oxy- 
gen into  CO,,  and  thus  reduce  the  iodate  and  convert 
it  into  an  iodid.  Description:  Colorless,  transparent, 
translucent  or  opaque,  white  cubical  crystals  or  a 
white  granular  salt,  with  faint,  iodin-like  odor,  pung- 
ent, saline,  afterward  bitter  taste.  Purity,  99%. 
Slightly  deliquescent  in  moist  air.  The  commercial 
salt  is  crystallized  from  an  alkalin  solution,  making 
it  more  stable,  and  occurs  in  white  crystals  having  an 
alkalin  reaction,  owing  to  the  presence  of  potassium 
carbonate.  The  chemically-pure  salt  should  have 
a  neutral  reaction.  Soluble  in  0.7  part  water,  12 
parts  alcohol,  2.5  parts  glycerin.  Incompatible  with 
lead  and  silver  salts.  Alterative.  Preparation: 
Ung.  Pot.  lodidi  (10%). 


150  PHARMACEUTK-    CHEMISTRY. 

Test  to  Detect  lodate. — Add  gelatinized  starch  and 
dilute  H2SO4.     A  blue  color  will  appear. 

Potassium  nitrate  (potassii  nitras  U.S.P.),  KNO3. 
Saltpeter,  niter,  Calcutta  niter.  Purity,  99%.  Found 
native  in  India.  Description:  Colorless,  transparent 
crystals  or  white,  crystalline  powder.  Odorless,  with 
a  cooling,  saline  taste.  Soluble  in  3.6  parts  water, 
sparingly  in  alcohol.  Obtained  by  lixiviating  the 
earth  from  the  niter  beds  of  India  and  filtering, 
evaporating  and  crystallizing.     Used  as  a  diuretic. 

Potassium  permanganate  (potassii  permanganas 
U.  S.  P.),  KMnO^.  Purity,  99%.  Comes  in  slender, 
monoclinic  prisms  of  a  dark  purple  color  and  a  blue 
metallic  luster  by  reflected  light.  Odorless;  taste  at 
first  sweet,  afterward  disagreeable  and  astringent. 
Used  as  antiseptic,  deodorant,  emmenagoguc.  Ad- 
ministered in  pill  form  with  kaolin  and  petrolatum. 
Made  by  boiling  a  solution  of  potassium  manganate 
with  water. 
sK^MnO,  +  2H20  =  2KMnO,+ MnO^  +  4KOH. 
Soluble  in  15  parts  of  water;  it  decomposes  in  con- 
tact with  alcohol  or  glycerin.  It  is  a  powerful  oxidiz- 
ing agent,  very  incompatible  with  reducing  agents, 
with  some  of  which  it  explodes  on  dry  trituration. 
It  should  not  be  brought  in  contact  with  organic 
substances. 

Potassium  sulfate  (potassii  sulphas  U.  S.  P.), 
K2SO4.  Purity,  99%.  Hard,  colorless,  transparent 
crystals  or  a  white  powder,  odorless,  having  a  some- 
what bitter,  saline  taste.  Soluble  in  9  parts  water, 
insoluble  in  alcohol.     Used  as  cathartic.     Made  by 


SODIUM.  151 

purifying  residue  from  nitric  acid  manufacture. 
Native  as  kainite.  Found  in  the  Stassfurt  salt  beds 
as  a  double  sulfate  of  potassium  and  magnesium. 
Made  directly  by  decomposing  common  niter  with 
H^SO^thus: 

2KNO3  +  H,SO,  =  K2SO,  +  2HNO3. 
Among  the  frequently  used   compounds  of   potash, 
is   potassa    sidphurata — sulfurated   potash    (liver  of 
sulfur).     Made  by  heating  together  sublimed  sulfur, 
I,  and  potassium  carbonate,  2. 

SODIUM,  Na,  23. 

Sources:  (i)  Sea  water;  (2)  mineral  springs;  (3) 
cryolite,  the  double  fluorid  of  sodium  and  aluminum; 
(4)  borax  lakes  of  California;  (5)  Chili  niter.  The 
salts  of  sodium  are  cheaper  and  more  frequently  used 
than  those  of  potassium.  As  a  rule,  they  are  also 
more  soluble. 

Sodium  hydroxid  (sodii  hydroxidum),  NaOH. 
Caustic  soda,  sodium  hydrate.  Known  in  the  last 
U.  S.  P.  as  "soda."  Prepared  from  slaked  lime  and 
sodium  carbonate.  The  solution  is  decanted  and 
evaporated.  The  crude  salt  is  largely  contaminated 
with  carbonate  and  called  "soda  ash." 

Na2C03  +  Ca(OH)3  =  2NaOH  +  CaCOj. 
Purity,  9o^/(,  and  not  more  than  2%  of  other  inor- 
ganic substances.  Description:  Dry,  white  flakes, 
fused  masses  or  sticks.  Soluble  in  i  part  water. 
Very  soluble  in  alcohol.  With  salts  it  forms  acids 
and  water.  Preparations:  Liq.  sodii  hydroxidi  (5%). 
Antacid.     The  chemically-pure  salt  is  prepared  by 


152  PHAKMAi  EUTIC    (IIEMISTKY. 

oxidizing  metallic  sodium   with  distilled   water  and 
evaporating. 

Sodium  acetate  (sodii  acetas  U.S. P.),  CHgCOONa 
-f3H20.  Description:  Large,  colorless,  trans- 
parent, monoclinic  prisms  or  granular  powder,  ef- 
florescent, odorless,  bitter  taste,  alkalin  reaction. 
Purity,  99.5%.  Made  by  decomposing  sodium 
carbonate  with  acetic  acid. 

2CH3COOH  +  Na^COg  =  2('H3COOXa  -h 
H2O  +  CO.. 
Sodium  acetate  is  soluble  in  1  part  water,  23  parts 
alcohol.     Used  as  diuretic. 

Sodium  arsenate  (sodii  arsenas),  XajHAsO^ + 
7H2O.  Purity,  98%  of  pure  disodium-orthoarsenate. 
Description:  Colorless,  transparent  crystals,  having 
a  mild,  alkalin  taste.  Very  poisonous;  soluble  in 
1.2  parts  water,  sparingly  in  alcohol;  precipitated  by 
tannic  acid.  Oxidizes  hypophosphites,  sulfites  and 
iodids.  Precipitates  alkaloidal  salts.  Used  as  tonic, 
alterative,  hematinic.  Made  l)y  heating  together 
arsenous  acid,  sodium  nitrate  and  carbonate,  which 
form  sodium  pyroarsenate.  The  pyroarsenate  is 
then  converted  into  the  orthoarsenate  by  dissolving 
it  in  water,  fdtering  and  crystallizing.  Thus: 
Na.As^Oy  +  15H2O  =  2Na.,HAsO,  +  7^,0. 

Exsiccated  sodium  arsenate  (sodii  arsenas  exsic- 
catus)  should  contain  not  less  than  98%  of  anhyd- 
rous disodium-orthoarsenate.  Prepared  by  drying 
the  crystals  at  a  temperature  between  40  and  50°  C. 
until  disintegrated,  then  at  150°  C.  until  they  cease 
to  lose  weight-     Description:  An   amorphous  white 


soniiur  coMi'oiiNDS.  .153 

])()wder,  odorless,  and  having  a  mild,  alkalin  taste. 
Preparations:  Liq.  sodii  arsenatis  (i'-/,). 
.  Sodium  Benzoate  (sodii  l)enzoas),  CgH^COONa. 
IHiritv,  9(/','.  Description:  A  white,  amorphous, 
granular  or  crystalline  powder;  odorless  with  a 
sweetish,  astringent  taste.  Soluble  in  1.6  parts 
water,  43  parts  alcohol.  Stronger  acids  precipitate 
it  from  its  solution.  It  precipitates  also  salts  of 
silver,  mercury  and  lead;  precipitates  pinkish  fer- 
ric benzoate  from  the  neutral  chlorid  and  solutions  of 
cjuinine  bisulfate.  Used  as  antiseptic,  expectorant, 
diuretic.  Made  by  decomposing  sodium  carbonate 
with  benzoic  acid. 

2C6H5COOH  +  Na2C03  =  2C6H5COONa  + 
CO2  +  H.,0. 

Sodium  bicarbonate  (sodii  bicarbonas),  NaHCOg. 
Purity,  99%.  Description:  A  white,  opaque,  powder, 
odorless  with  a  cooling,  mildly  alkalin  taste.  Also 
called  "baking  soda"  and  soda  saleratus.  Made  by 
washing  commercial  NaHCOg  with  HjO.  Solvay's 
process  : 

NaCl  +  NH3  +  CO2  +  H2O  =  NaHCOg  +NH,C1. 
Preparation:  Troch.  sodii  bicarb.  Solubility:  12 
parts  water. 

Sodium  bisulfite  (sodii  bisulphis),  NaHSOg. 
Purity,  90%.  Description :  Opaque,  prismatic 
crystals  or  granular  powder  with  odor  of  SOj  and  a 
disagreeable  sulfurous  taste.  Exposed  to  the  air, 
it  is  gradually  oxidized  to  a  sulfate.  Made  by 
saturating  sodium  carbonate  with  sulfurous  acid. 
NaXO,,  +  2H.,S0,  =  2NaHS0,  +  CO.,  +  U.O. 


154  PHARMACEUTIC    CHEMISTRY. 

Soluble  in  3.5  parts  water,  70  i)arts  alcoliol.      Incom- 
patible with  acids.     Antiseptic. 

Sodium  borate  (sodii  boras),  NajB^O^  +  loH^O. 
Borax.  Purity  not  less  than  99%  of  pure  sodium 
tetraborate  (orthoborate).  Description:  Colorless 
crystals  or  a  white  powder,  having  a  sweetish, 
alkalin  taste.  Soluble  in  20.4  parts  water,  i  part 
glycerin;  insoluble  in  alcohol.  Incompatible  with 
neutral  solutions  of  many  metals.  Also  with  alum, 
calcium  chlorid  and  barium  chlorid.  With  mineral 
acids,  boric  acid  is  precipitated  out. .  It  precipitates 
alkaloidal  salts;  glycerin,  glucose  or  honey  liberate 
boric  acid  from  solutions  of  borax,  rendering  them 
incompatible  with  carbonates.  Mild  antiseptic. 
Made  by  i)urifying  the  neutral  salts  found  as  a 
crystalline  dej)osit  in  the  blue  mud  of  Clear  Lake, 
California.  It  is  alst)  called  timal.  Found  in 
Tuscany  as  crude  boric  acid. 

Sodium  bromid  (sodii  bromiduni  U.  S.  P.),  NaBr. 
Purity,  when  dried,  97%.  Description :  Colorless  or 
white  cubical  crystals  or  granular  powder,  saline, 
with  bitter  taste.  Absorbs  water  from  the  air  w  ithout 
deliquescing.  Soluble  in  1.7  parts  water,  12.5  parts 
alcohol.  Incompatible  with  alkaloidal  salt  solutions. 
Made  by  treating  ferrous  bromid  with  sodium  car- 
bonate,    liltering,     evaporating     and     crystallizing. 

FeBr,  +  Na.CO.,  =  2NaBr  +  FeCOj. 
Used  as  sedative  nervine. 

Monohydratcd  sodium  carbonate  (sodii  carbt  nas 
mcmohydratus  U.  S.  P.),  Na,CC),  +  HjO.  Purity, 
85%  of  pure  anhydrous  salt,  corresponding  to  99.5% 


SODIUM    CARBONATE.  1 55 

of  the  crystallized  salt.  Description:  Monohy- 
drated  sodium  carbonate  is  a  white,  crystalline, 
granular  powder,  odorless,  with  strong  alkalin  taste. 
It  effloresces  at  50  C,  and  at  100°  C.  loses  its  water 
of  crystallization  (14.5%).  Leblanc's  process:  Com- 
mon salt  is  converted  into  the  carbonate  by  two 
steps: 

ist  step:  into  the  sulfate: 

2NaCl  +  H2SO,=Na2SO,  +2HCI. 
2d  step:  the  sulfate  with  charcoal  into  carbonate: 
Na2SO,  +  C,  +  CaC03  =  Na2C03  +  CaS  +  4CO. 
This  mass  is  now  digested  in  warm  water  which  dis- 
solves out  the  alkali,  leaving  behind  the  insoluble 
"soda  waste,"  which  latter  is  used  in  the  manufacture 
of  sodium  hvposulfite.  The  above  solution  is 
evaporated  to  dryness  and  the  mass  calcined  with 
sawdust,  which  converts  the  alkali,  owing  to  its  COj, 
fully  into  carbonate.  This  is  redissolved,  filtered  and 
evaporated.  This  "soda  ash"  contains  about  50%  of 
sodium  carbonate.  The  CryoHte  process  is  used  in 
the  United  States:  Cryolite,  a  double  fluorid  of  alumi- 
num and  sodium  (Al2Fg.6NaF)  is  heated  with  chalk. 
The  mass  is  leached  by  Hxiviation.  The  alumina 
becomes  insoluble  and  is  deposited.  The  liquid  is 
filtered,  purified  and  crystallized.  In  the  U.  S.  P.  '90, 
sodii  carhonas  was  official,  a  salt  which  contained  ten 
molecules  of  water  of  crystallization.  This  has  been 
supplanted  with  the  monohydrated  sodium  car- 
bonate. Sodii  carbonas  exsiccatus  (dried)  was  also 
official.  Used  as  antacid.  Solubility:  2.9  parts 
water,  8  parts  glycerin,  insoluble  in  alcohol  and  ether. 


156  PHARMACKUTIC    CHEMISTRY. 

Sodium  chlorate  (sodii  chloras  U.  S.  P.),  NaClOj. 
Purity,  99*^0-  Colorless,  transparent  crystals  or  a 
crystalline  powder;  odorless,  cooling  saline  taste. 
Soluble  in  i  part  water,  5  parts  glycerin,  100  j^arts 
alcohol. 

Caution:  Sodium  chlorate  is  explosive  when  heated 
or  triturated  with  organic  substances  or  oxidizable 
bodies.  Made  by  the  Witt  stein  process,  from  sodium 
carbonate  and  tartaric  acid. 

Na2C03  +  2H,C,H,0,=  2NaHC,H,06+C02  +  H.,0. 

Then  the  bitartrate  is  added  to  potassium  chlorate. 

NaHC.H.Og  +  KCIO3  =  NaClO.,  +  KHC^H^Og. 

Note. — When  this  salt  is  prescribed,  under  no  cir- 
cumstances should  sodium  chlorid  be  dispensed. 

Sodium  chlorid  (sodii  chloridum),  NaCl.  Sal 
communis,  sal  culinaris,  common  salt.  Purity,  when 
dried,  99%.  Description:  colorless,  transparent 
cubical  crystals  or  a  white,  crystalline  powder. 
Permanent  in  dry  air,  pure  saline  taste,  obtained  by 
evaporating  sea-water  and  the  brine  from  salt  wells 
and  springs.  When  magnesium  chlorid  is  present 
as  impurity,  the  salt  is  very  deliquescent. 

Sodium  citrate  (sodii  citras),  2Na3C„H.-C)7  -{- 
11H2O.  Purity,  97%.  A  white,  odorless,  granular 
powder,  having  a  cooling,  saline  taste.  Effloresces 
slowly.  Prepared  by  adding  sodium  carbonate  to  a 
solution  of  citric  acid  until  efTervescence  ceases, 
evaporating  and  granulating.  Soluble  in  i.i  parts 
water,  slightly  in  alcohol.     Diuretic. 

Sodium  hypophosphite  (sodii  hy])o])ln)Si)his\ 
NaPH,(X-|-ir,().    Purity,  98C; .     Description:  ^m:i\\. 


SODIUM   COMPOUNDS.  157 

colorless,  transparent  plates  of  pearly  luster  or  white 
granular  powder.  Odorless,  bitterish,  saline  taste. 
Very  deliquescent.  Made  by  double  decomposition 
between  calcium  hypophosphite  and  sodium  car- 
bonate. (See  reaction  under  potassium  hypophos- 
phite.) The  salt  explodes  with  violence  during 
evaporation  which  should,  therefore,  be  performed 
below  100° — better  at  85°  C.  Soluble  in  i  part 
water,  25  parts  alcohol;  insoluble  in  ether.  Used  as 
tonic.  Preparations:  Syr.  hypophosphitum  (1.5%) 
and  syr.  hypophos.  comp.  (1.75%). 

Sodium  iodid  (sodii  iodidum),  Nal.  Purity,  98%. 
Colorless,  cubical  crystals  or  crystalline  powder. 
Description:  Odorless,  with  saline,  bitterish  taste. 
Soluble  in  0.5  part  water,  3  parts  alcohol.  In  moist 
air  the  salt  decomposes,  assuming  a  brown  tint. 
Alterative.     Preparation: 

Fel.  +  Na2C03  =  2NaI  +  FeCO,. 
Insoluble  iron  carbonate  is  filtered  off.     The  solution 
is  then  evaporated  and  crystallized. 

Sodium  nitrate  (sodii  nitras),  NaNOg.  Chili 
saltpeter,  cubic  niter.  Purity,  99%.  Found  native 
in  Chili  and  Peru.  Obtained  by  lixiviation,  evapo- 
ration and  crystallization.  Colorless,  transparent, 
rhombohedral  crystals,  odorless,  cooling,  saline, 
bitterish  taste.  Hygroscopic.  Soluble  in  i.i  parts 
water  and  100  parts  alcohol.  Diuretic.  This  salt 
constittites  the  cheapest  source  for  obtaining 
nitrates. 

Sodium  nitrite  (sodii  nitris),  NaNOj.  Should 
contain  not  less  than  go%  of  the  pure  salt.     Descrip- 


158  I'llAR.MACKlTIC    CHEMISTRY. 

lion:  White,  opaque  fused  masses  or  pencils  or 
transparent,  hexagonal  crystals.  Odorless,  mild 
saline  taste.  Very  deliquescent;  gradually  oxidizes 
and  is  converted  into  sodium  nitrate  and  becomes 
unfit  for  use.  Soluble  in  1.4  parts  water,  sHghtly 
in  alcohol.  Incompatible  with  hypophosphites,  sul- 
fites, iodids,  ammonium  bromid.  It  reduces  chlor- 
ates, permanganates,  chromates,  hydrogen  dioxid, 
mercurous  and  mercuric  salts.     Vasodilator. 

Sodium  phenol -sulfonate  (sodii  phenol-sulphonas), 
NaCgHjSO^  -I-  H2O.  Purity,  99%  of  pure  sodium 
paraphenol-sulfonate.  Description:  Colorless,  trans- 
parent, rhombic  prisms,  made  by  dissolving  sodium 
carbonate  in  phenol-sulfuric  acid.  Soluble  in  4.8 
parts  water,  130  parts  alcohol.     Antiseptic. 

Sodium  phosphate  (sodii  phosphas),  Na^HPO^ 
4-12H2O.  Purity,  in  the  uneffloresced  condition, 
99%  of  pure  disodium-orthophosphate.  Description  : 
Large,  colorless  prisms  or  granular  salt.  Odorless, 
cooling,  saline  taste.  Crystals  effloresce  in  the  air, 
losing  5  molecules  (25%)  of  their  water  of  crystal- 
lization. Cholagogue.  Soluble  in  5.5  parts  water. 
The  salt  contains  60.3%  of  water  of  crystallization. 
It  precipitates  nearly  all  other  metals,  some  of  the 
alkaloidal  salts,  and  liquefies  when  triturated  with 
lead  acetate,  phenol,  chloral  hydrate  or  salicylic 
acid.  Prepared  by  dissolving  calcined  bones  (neutral 
calcium  phosphate)  in  concentrated  sulfuric  acid. 
Acid  calcium  phosphate  is  formed.  By  boiling  this 
solution  with  sodium  carbonate  the  phosphoric  acid  is 


SODIUM    COMPOUNDS.  I  59 

completely  saturated  and  the  calcium  is  thrown  down 
as  insoluble  calcium  sulfate. 

(1)  Ca3(PO,)2  +  2H2SO,  =  CaH,(PO,)2  +  2CaSO,. 

(2)  CaH,(P0,)2  +  Na^COg  =  Na,HPO,  + 
CaHPO, +H,0+  CO.,. 

The  calcium  phosphate  is  separated  by  filtration  and 
the  filtrate  evaporated  and  crystallized. 

Exsiccated  sodium  phosphate  (sodii  phosphas 
exsiccatus).  Purity,  99%  of  pure  anhydrous  salt. 
Description:  A  white  powder  which  absorbs 
moisture  readily.  Made  by  allowing  crystalline 
sodium  phosphate  to  effloresce  for  several  days  in 
warm  air  at  between  25  to  30°  C,  then  drying  in  an 
oven  at  100°  C.  until  constant  weight. 

(Sodii  phosphas  effervescens)  effervescent  sodium 
phosphate  is  made  from  the  exsiccated  sodium  phos- 
jjhate — 2o^( . 

Sodium  pyrophosphate  (sodii  pyrophosphas), 
Na^PjO^  +  10H2O.  Purity,  99%.  Description: 
Colorless,  transparent  prisms  or  crystalline  powder. 
Odorless,  with  cooling,  feebly  alkalin  taste.  Slightly 
efflorescent.  Made  by  heating  sodium  phosphate  to 
redness,  dissolving  and  crystallizing.  Soluble  in 
1 1.5  parts  water;  insoluble  in  alcohol.  It  precipi- 
tates solutions  of  metallic  salts.  Used  in  the  prepa- 
ration of  ferric  pyrophosphate. 

Sodium  saKcylate  (sodii  salicylas)  CgH^(OH)- 
COONa.  Purity,  99.5%.  Description:  White, 
microcrystalline  powder  or  scales  or  an  amorphous, 
colorless  powder,  having  not  more  than  a  faint, 
pink  tinge.     Odorless,  sweetish,  saline  taste.     Sol- 


l6o  PHARMACEUTIC    CHEMISTRY. 

uhlc   in   0.8  part  water,  5.5   i)arts  alcohol,  also  in 
glycerin.     Antiseptic,  cholagogue,  antirheumatic. 
2C6H,(OH)COQH  +  Na.,C03  =  2CeH,(OH)CQONa 

I     U  Q     I     CO  sodium  salicylate 

For  internal  administration  only  the  salt  i;repari(l 
from  oil  of  wintergreen  should  be  dispensed. 

Sodium  suljate  (sodii  sulphas),  NajSO^  +  ioH._,(,). 
Glauber's  salt.  Purity,  in  the  uneffloresced  con- 
dition, 99%.  Description:  Large,  colorless,  trans-, 
parent  prisms  or  granular  crystals.  (Morless,  saline, 
bitter  taste.  The  salt  effloresces  rapidly  in  the  air 
and  quickly  loses  all  of  its  water  of  crystallization. 
Made  bv  decomposing  common  salt  with  sulfuric 
acid.  Soluble  in  2.8  parts  water,  also  in  glycerin; 
insoluble  in  alcohol.  When  heated.it  dissolves  in 
its  own  water  of  crystallization.  Incompatible  witii 
metallic  chlorids.     Used  as  hydragogue  cathartic. 

Sodium  sulfite  (sodii  sulphis),  Na^SOj  -1-  7H,(). 
Purity,  in  the  uneffloresced  and  air-dried  condition, 
96%.  Description:  Colorless,  transparent,  mono- 
clinic  prisms,  odorless,  cooling,  saline  and  sulfurous 
taste,  effloresces  on  exposure,  and  slowly  oxidizes 
to  a  sulfate.  Soluble  in  2  parts  water,  sparingly  in 
alcohol.  It  is  decomposed  by  acids.  Used  as 
antiseptic.  The  salt  is  made  by  passing  SO,  gas 
into  a  solution  of  sodium  carbonate,  thus  forming 
sodium  bisulfite,  mixing  this  with  an- equal  weight 
of  sodium  carbonate,  neutral  sulfite  is  formed. 
Na,CC).,  +  SO,  =  Na,SO,  -f  CO... 

Sodium  thiosuljate  (sodii  thiosulphas),  Na,S._,0;, 
-(-  qli.O  (sodii  hyp()suli)his  U.  S.  P.   \)o)  "hyposul- 


.     AMMONIUM.  l6l 

fite."  Purity,  98%.  Description:  Colorless,  trans- 
parent, monoclinic  prisms.  Permanent  below  33°  C, 
but  efflorescent  above  that  temperature.  Deliquescent 
in  moist  air;  odorless;  cooling,  somewhat  bitter  taste, 
neutral  reaction.  Made  by  decomposing  calcium 
thiosulfate  with  sodium  sulfate.  Soluble  in  0.35  part 
water,  slightly  in  oil  of  turpentine;  insoluble  in  alco- 
hol. Incompatible  with  acids;  precipitates  barium, 
silver,  lead  and  mercurous  salts  from  aqueous  solu- 
tions. In  acid  solution  it  is  a  powerful  reducer, 
incompatible  with  oxidizing  agents.  The  tritura- 
tion of  it  with  strong  oxidizing  substances  results  in 
explosion.  Antiseptic.  Used  in  photography. 
CaS.,03  +  Na^SO,  =  Na2S303  +  CaSO,. 

AMMONIUM,  NHj,  18. 

Source. — Coal-gas  liquor,  which  is  the  by-product 
in  the  manufacture  of  boneblack.  Ammonium 
(NH^)  is  a  compound  of  nitrogen  and  hydrogen.  It 
is  not  found  free  and  has  never  been  isolated.  It  is 
a  radical,  also  called  a  "quassi  metal"  and  classed 
with  the  alkalis  for  convenience  only.  Ammonia 
(NH3)  is  a  saturated  compound  capable  of  existing 
in  the  free  state.  It  occurs  in  the  atmosphere,  in 
natural  waters  and  in  the  earth.  Difference  between 
the  salts  of  the  alkalis  and  ammonium  is  but  one: 
all  ammonium  salts  are  volatile  at  a  moderate  tem- 
perature, the  other  alkali  salts  are  not.  Remember 
the  difference  between  (NH3),  a  saturated  com- 
pound, and  ammonium,  a  radical  (NHJ.  In 
ammonia  the  nitrogen  is  a  triad;  in  ammonium  it 
is  a  pentad. 


l62  PHARMACEUTIC    CllKMlS TRY. 

Compounds: 

Ammonium  benzoale  (ammonii  benzoas),  XH^C";- 
H5O2.  Purity,  98%.  Description:  Thin,  white, 
Hminar  crystals  or  powder;  odorless;  saline,  l)iiter, 
slightly  acrid  taste.  Soluble  in  10.5  parts  water, 
25  parts  alcohol.  Used  as  antiseptic,  expectorant, 
diuretic.  Made  by  dissolving  benzoic  acid  in 
ammonia  water. 

HC7H5O2  +  NH,(OH)  =  NH.C^HgO.,  +  H.,(). 
Ammonium  bromid  (ammonii  bromidum),  NH^Br. 
Purity,  qfi{.  Should  be  preserved  in  well-stoppered 
bottles.  Colorless,  prismatic  crystals  or  crystalline 
powder;  odorless,  with  pungent,  salty  taste.  Soluble 
in  1.2  parts  water;  12.5  parts  alcohol.  Sedative 
nervine.  Made  by  Pile's  process  of  adding  ammonia 
water  to  bromine  water: 

6Br  +  8NH3  =  6NH,Br  +  N,. 
Ammonium  carbonate  (ammonii  carbonas),  C^Hji- 
N3O5.  Should  contain  not  less  than  97%  of  a  mixture 
of  ammonium  bicarbonate  and  ammonium  carbamate, 
and  should  yield  not  less  than  31.58%  of  ammonia 
gas.  For  dispensing  purposes,  only  the  translucent 
portions  should  be  used.  The  opaque,  friable  white 
powder  or  porous  lumps  on  the  outside  are  the  inert 
ammonium  bicarbonate,  and  should  be  rejected. 
Also  known  as  "baker's  ammonia,"  sal  volatile, 
hartshorn.  Description:  White,  hard,  translucent 
masses,  with  strong  ammoniacal  odor  and  a  sharp 
saline  taste.  Changes  to  white  powder  on  ex])osure 
to  the  air.  Soluble  in  4  jiarts  water;  alcohol  dis- 
solves   the    carbamate,    but    not    the    liicarbonate. 


AMMONIUM    COMPOUNDS.  1 63 

When  the  official  salt  is  dissolved  in  water  containing 
ammonia  gas,  it  is  converted  into  the  true  carbonate, 
the  formula  for  which  is  (NH4)2C03,  according  to 
the  following  reactions: 

From  the  carbamate: 

{a)  NH^.NH^.COg  +  H^O  =  (NHJ^COg. 

From  the  bicarbonate : 

(h)  NH.HCOg  4-  NH3  =  (NHJXO3. 

The  salt  is  made  by  subliming  a  mixture  of 
ammonium  sulfate  and  calcium  carbonate: 

2(NH,)2SO,  +  2CaC03  =  NH,HC03.NH,NH,CO, 
+  H2O  +  NH3  +  2CaSO,. 

Used  as  a  reflex  stimulant,  carminative,  expectorant. 
Preparations :  Liquor  ammonii  acetatis  (5%) .  Incom-. 
patible  with  mercuric  chlorid,  calomel,  copper  and 
silver  salts,  alkaloidal  salts.  It  should  be  dispensed 
with  care  with  syrups  of  squills,  ipecac  and  of  citric 
acid  or  any  syrup  containing  an  acid. 

Ammonium  chlorid  (ammonii  chloridum),  NH^Cl. 
Sal  ammoniac,  muriate  of  ammonia,  battery  ammonia. 
Purity,  99.5%.  Description:  White  crystalline  pow- 
der, permanent,  odorless,  cooling,  saline  taste,  with  a 
neutral  reaction.  Soluble  in  2  parts  water,  50  parts 
alcohol  and  5  parts  glycerin,  and  i  part  boiling 
water.  Made  by  subliming  a  mixture  of  ammonium 
sulfate  (a  by-product  from  gas  manufacture)  and 
sodium  chlorid. 

(NHJ2SO,  +  2NaCl  =  Na^SO,  +  2NH,C1. 
Incompatible  with  alkali  hydrates  or  carbonates  or 
the  hydroxids  of  the  earthy  metals  which  liberate 
NH3    gas    from     it.     With    chlorin    gas    explosive 


164  I'HAKMACEUTIC    CHEMISTRN  . 

nitrogen  chlurid  may  he  furnifd.  Ivxpectorant. 
hepatic  stimuhmt.  Preparations:  Troeh.  amnionii 
(  hioricii   (o.i   gni.  each). 

Ammonium  iodid  (ammonii  iodidum),  NH^l. 
Purity,  97%.  When  deeply  colored,  the  salt  should 
not  he  dispensed.  It  may  be  deprived  of  free  iodin 
hy  adding  to  its  concentrated  solution  ammonium 
sultid  sufficient  to  decolorize  it,  fdtering,  evaporat- 
ing on  water-hath  to  dryness.  Description:  Minute, 
cubical  crystals  or  white,  granular  powder;  when 
colorless  without  odor,  but  emitting  odor  of  iodin 
when  colored.  Sharp,  saline  taste,  very  hygroscopic. 
Made  by  mixing  solutions  of  potassium  iodid  and 
ammonium  sulfate. 

2KI  +  (NH,),S(),  -  2NHJ    +  K.,SO,. 
Soluble  in  0.6  part  water,  9  parts  alcohol.     Alterative. 

Ammonium  salicylate  (ammonii  saHcylas),  NHiC^- 
H.O,,.  Purity,  98^,.  Should  l)c  protected  from 
heat  and  light  and  preserved  in  well-stoppered 
l)ott!es.  Description:  Colorless,  lustrous  crystals 
or  plates  or  crystalline  powder.  Odorless,  with  a 
slightly  saline,  bitter  taste,  and  a  sweetish  after- 
taste. Made  by  neutralizing  ammonia  water  with 
.salicylic  acid,  evaporating  and  crystallizing.  Soluble 
in  0.9  part  water,  2.1,  parts  alcohol.  Used  as  anti- 
septic, cholagogue  and  antirheumatic. 

Ammonium  valerate  (ammonii  valeras),  NH4C.:i- 
H„( ).,.  (Ammonii  valerianas  U.  S.  P.  'go.')  Descrip- 
tion: Colorless  or  white,  ([uadrangular  plates, 
emitting  the  odor  of  valeric  acid,  with  a  sharp, 
sweetish    taste;   deliquescent    in    moist   air.     Purity, 


AMMONIUM   COMPOUNDS.  1 65 

(j8'\ .  Should  hf  preserved  in  stoppered  bo.ttles. 
Made  by  passing  ammonia  gas  into  valerianic  acid. 
The^alt,  as  found  in  commerce,  is  generally  the  acid 
salt  and  should  be  neutralized  with  ammonia  when 
used  in  solution  for  making  preparations  like  the 
various  elixirs.  Very  soluble  in  water  and  in  alcohol ; 
also  soluble  in  ether.  Incompatible  with  hydroxids 
and  carbonates  and  sulfuric  acid.     Antispasmodic. 

It  should  be  noted  that  Ammonia  combines 
with  acids  and  the  halogens  to  form  corresponding 
salts.  Ammonium  iodid  is  readily  decomposed 
into  nitrogen  iodid,  which  is  very  explosive.  Am- 
monia water  precipitates  solutions  of  mercury,  lead, 
silver,  copper,  zinc,  bismuth,  iron,  manganese, 
aluminum,  chromium,  antimonx'.  With  mercurous 
chlorid  it  forms  a  black  precipitate.  It  also  precijii- 
tates  tartaric  and  picric  acid  solutions.  With  the 
latter  acid  it  forms  the  powerfully  explosive  ammo- 
nium picrate.  Ammonia  precipitates  nearly  all 
alkaloids  from  their  salt  solutions.  It  decomposes 
chloral  into  chloroform  and  a  formate.  When 
boiled  with  solutions  of  formaldehyd,  hexamethy- 
lenamin  (urotropin)  forms.  Permanganates  oxidize 
it  to  nitrate.  Reactions:  with  phenol,  blue  color  is 
slowly  developed;  with  gallic  acid,  yellow  to  reddish - 
brown  coloration ;  with  thymol,  green  color  is  formed. 
Preparations:  Aqua  ammoniae  (lo*^,-),  sp.  gr.,  0.958; 
aqua  ammoniae  fortior  (28%),  sp.  gr.,  0.897;  spiritus 
ammoniae  (10%);  spir.  ammoniae  aromaticus  (am- 
monia water,  9%;  lin.  ammoniac  (ammonia  water, 
35%)- 


l66  PHARMAnaXIC   ciiemistrv. 

MAGNESIUM,  Mg,  24.     Sp.,  gr.,  1.75. 

Occurrence. — Very  abundant  metal,  not  found 
free  in  nature.  Many  of  its  mineral  compounds,  as 
talc,  asbestos,  soapstone,  magnesite,  dolomite,  kie- 
serite  and  meerschaum,  are  very  familiar.  .\s  a 
sulfate,  it  is  found  in  many  saline  springs,  as  the 
Epsom,  of  England,  and  as  chlorid  in  sea-water. 
The  silver-white  metal  magnesium,  in  the  form  of  a 
ribbon  or  wire,  when  held  in  a  flame  burns  with  an  in- 
tensely active  flame,  producing  a  bulky,  white  i)re- 
cipitate.     Four  magnesium  salts  are  official. 

Magnesium  carbonate  (magnesii  carbonas  U.  S.  P.), 
(MgC03),.Mg(OH)2  +  5H,0.  When  ignited,  it 
should  yield  40%  of  residue,  of  which  96%  should  be 
pure  magnesium  oxid.  Light,  white  friable  masses 
or  a  bulky  powder;  odorless  with  an  earthy  taste;  per- 
manent Made  by  double  decomposition  between 
magnesium  sulfate  and  sodium  carbonate.  When 
the  solutions  are  made  in  boiling  hot  water,  the  heavy 
carbonate  results.  When  the  cold  solutions  are  em- 
ployed the  light  carbonate  is  the  product.  Insoluble 
in  water  and  alcohol;  dissolves  in  dilute  acids  with 
effervescence.  Antacid,  laxative.  Preparations: 
Liq.  magnesii  citratis. 

SMgSO,  -f  5Na.,CO,  -f  H.,0  =  4MgC03.Mg(OH), 
+  SNa.SO,  -h  CO,. 

Magnesium  oxid  (magnesii  oxidum  U.S. P.),  MgO 
Magnesia  (magnesia  U.  S.  P. '90),  calcined  magne- 
sia, light  magnesia,  magnesia  levis).  Purity:  after 
ignition,  it  should  }ield  96%  of  pure  magnesium 
oxid,   a    white,    ver\-    l)ulk\-   and    vcrx-    luu'    powder. 


MAGNESIUM.  1 67 

slowlv  al)S()rl)ing  moisture  and  CO.  from  the  air. 
Odorless,  with  earthy  taste.  Made  by  calcining 
light  magnesium  carbonate. 

(MgC03),.Mg(OH)2  +  5H,0  =  sMgO  +  4CO, 
+  6H2O. 

Almost  insoluble  in  water;  dissolves  in  acids.  With 
15  times  its  weight  of  water  it  gelatinizes  forming 
a  hydrate.     Antacid. 

Heavy  magnesium  oxid  (magnesii  oxidum  ponder- 
osum  U.  S.P.),  MgO  (magnesia  ponderosa  U.  S.  P. 
'90),  heavy  magnesia.  A  white,  dense  and  very  fine 
powder  which  should  conform  to  the  reactions  and 
tests  given  under  magnesii  oxidum.  It  differs  from 
the  latter  in  not  readily  uniting  with  water  to  form  a 
gelatinous  hydroxid.  The  salt  is  similar  to  the 
light  magnesia,  except  in  possessing  only  one-fourth 
the  bulk  which  facilitates  its  administration.  It  is 
prepared  by  calcining  heavy  magnesium  carbonate 
which  is  produced  by  precipitating  a  hot,  concen- 
trated solution  of  magnesium  sulfate  with  sodium 
carbonate.  The  salt  is  soluble  in  acids;  insoluble 
in  water  and  alcohol.  Used  as  antacid  and 
laxative. 

Magnesium  sulfate  (magnesii  sulphas),  MgSO^ 
-(-  7H2O,  commonly  called  Epsom  salt,  after  the 
English  spring  in  which  it  is  found.  It  is  also 
manufactured  from  the  mineral  kieserite,  which  is  an 
impure  sulfate  containing  but  one  molecule  of  water 
of  crystallization.  Four-sided  prisms  or  acicular 
crystals.  Odorless,  cooling,  saline,  bitter  taste. 
Slowlv  efflorescent  in  the  air.     Soluble  in  0.85  part 


l68  PlfAKMACKl'TIC    CHEMISTRY. 

water  and  in  0.13  parts  hot  water;  insoluble  in 
alcohol.  Used  for  the  jireparation  of  the  carbtinate. 
Soluble  magnesium  salts  are  precipitated  by  soluble 
hydroxids  and  carbonates  (except  ammonium  salts) 
and  by  phosphates,  arsenates,  sulfites,  oxalates  and 
tartrates;  also  incompatible  with  the  chlorids  of  the 
heavy  metals.  Used  as  hydragogue  purgative. 
Preparations:    Magnesii  sulphas  effervescens  (5o9c). 

Tests. — The  follow-ing  method  may  be  employed 
to  detect  the  metals  of  this  group.  To  a  portion  of 
the  solution  add  sodium  hydroxid  and  heat  in  a  test- 
tube.  The  formation  of  ammonia,  which  may  be 
detected  by  its  odor  or  action  on  test  papers  or  white 
fumes  with  hydrochloric  acid  prove  the  presence  of 
a mmonium  compounds. 

To  a  second  portion  add  ammonium  chlorid,  am- 
monium hydroxid  and  sodium  phosphate.  A  white, 
crystalline  precipitate  of  ammonium  magnesium 
phosphate  proves  the  presence  of  magnesium. 

Evaporate  a  third  and  quite  a  large  portion  of  the 
original  solution  to  dryness  and  ignite  sufficiently  to 
volatilize  all  ammonium  salts.  Dissolve  the  resi- 
due in  a  small  amount  of  water,  add  a  drop  of 
hydrochloric  acid.  Dip  a  clean  platinum  wire 
formed  into  a  small  loop  into  the  solution  and  place  it 
in  the  Bunsen  flame.  An  intense  yelloiv  color  indi- 
cates sodium;  a  lilac  or  grayish-purple  color  shows 
potassium.  Examined  through  a  polariscope,  potas- 
sium is  indicated  by  a  crimson  line.  Add  t<^  the 
solution  of  the  above  residue  a  few  drops  of  platinic 
(■lil(ui(l  solution:     A  yclhnc  precipitate  of  potassium 


PERIODIC    LAW.  169 

platino-chlorid  confirms  potassium.  Lithium  in 
solution  imparts  a  brilliant  carmine-red  to  the  fiamc. 
Disodium  phosphate  boiled  with  the  lithium  solution 
produces  an  insoluble  lithium  phosphate.  This  pre- 
cipitation is  complete  when  sodium  hvdroxid  is 
present. 

CLASSIFICATION  OF  THE  ELEMENTS  ACCORD- 
ING TO   "PERIODIC  LAW." 

As  has  already  been  noticed,  the  nonmetallic 
elements  seem  to  arrange  themselves  into  groups  or 
families.  The  halogens,  for  example,  obviously 
form  a  group  of  closely  related  elements;  and  it  is 
found  that  in  such  a  group  there  is  a  more  or  less 
regular  increase  in  the  atomic  weights.  Thus,  the 
atomic  weight  of  bromin  (80)  is  nearly  the  mean  be- 
tween the  atomic  weights  of  chlorin  and  iodin. 

2 

Carbon  and  silicon,  oxygen  and  sulfur,  nitrogen  and 
phosphorus  are  similarily  related.  Among  the 
metals,  we  have  the  group  lithium,  sodium  and 
potassium;  the  continuation  of  the  nitrogen  family — 
arsenic,  antimony  and  bismuth,  etc.  John  New- 
lands  (1864)  pointed  out  that,  if  the  elements  were 
arranged  in  the  numerical  order  of  their  atomic 
weights,  there  was  a  recurrence  of  similarity  in 
chemical  and  physical  properties  at  every  eighth 
element.     He  called  this  "The  Law  of  Octaves." 


[70  PlIARMAri-:UTIC    CHEMISTRY. 


NEWLAND'S  CLASSIFICATION  OF  THE 
ELEMENTS. 


Atomic  weigh 

t 

Atomic  weight 

Lithium, 

7 

Sodium, 

23 

Berylh'um, 

9 

^Lagnesium, 

24 

Boron, 

II 

Aluminum, 

27 

Carbon, 

12 

Silicon, 

28 

Nitrogen, 

14 

Phosphorus, 

31 

Oxygen, 

16 

Sulfur, 

?,2 

Fluorin 

19 

Chlorin, 

35-5 

About  five  years  a 

fterw 

arc] 

s  this  idea  was 

worked 

out  more  fully  by  Mendelejeff,  who  published  a  table 
of  the  elements  arranged  according  to  his  "Periodic 
Law,"  as  represented  on  page  173. 

The  following  points  should  be  noticed: 
(a)  After  the  first  two  octaves  (lithium  to  chlorin), 
the  resemblance  is  most  marked  between  alternate 
rather  than  between  consecutive  octaves;  thus,  tak- 
ing the  second  vertical  column,  magnesium,  zinc  and 
cadmium  form  a  natural  group,  and  the  other  alter- 
nate octaves,  calcium,  strontium  and  barium,  form  a 
second  natural  group. 

{h)  After  manganese,  a  triplet  of  metals  occurs — 
iron,  nickel  and  cobalt — forming  a  sort  of  supple- 
mentary eighth  vertical  column;  the  other  triplets  are 
ruthenium,  rhodium  and  palladium,  and  osmium, 
ir'dium  and  platinum.  The  atomic  weights  in  each 
of  these  triplets  are  close  together;  thus,  Fe,  56; 
Co,  59;  Ni,  58.3.  All  these  metals  have  high  melting- 
points. 


PERIODIC    LAW.  171 

(c)  The  valences  of  the  elements  may  he  said  to  in- 
crease as  we  pass  from  the  first  to  the  seventh  column ; 
thus:  sodium  is  a  monad;  magnesium,  a  dyad;  alumi- 
num, a  triad;  carbon,  a  tetrad;  nitrogen,  a  pentad; 
sulfur,  a  hexad;  manganese,  a  heptad;  the  same  fact 
is  indicated  by  the  formulas  of  the  oxids  at  the  top  of 
the  table.  On  the  other  hand,  the  compounds  with 
hydi-ogen  show  a  diminishing  number  of  atoms  of 
hydrogen  in  the  molecule  as  we  pass  from  left  to 
right;  thus,  CH„  NH3,  OH,,  CIH. 

Outside  the  great  theoretical  interest  of  this 
classification,  it  is  of  a  practical  use  in  several  ways: 

(i)  As  a  check  on  the  atomic  weights;  thus,  tel- 
lurium is  an  element  which  closely  resembles  selen- 
ium and  sulfur;  its  old  atomic  weight  was  128,  which 
would  place  it  after  iodin  in  a  group  to  which  it  was 
obviously  not  related;  recent  determinations  have 
reduced  the  number  to  127,  and  it  seems  extremely 
probable  that  it  has  not  been  obtained  perfectly  pure. 
The  atomic  weight  of  indium  is  38,  and  its  atomic 
weight  was  at  one  time  believed  to  be  38  X  2  =  76, 
but  as  there  is  no  space  for  an  element  between 
arsenic  and  selenium,  it  was  suggested  that  its  atomic 
weight  must  be  38  X  3  =  114,  which  would  place  it 
in  the  column  under  aluminum.  This  number  was 
actually  confirmed  by  determining  its  specific  heat. 

(2)  The  classification  enables  us  to  prophesy  the 
existence  and  properties,  physical  and  chemical,  of 
undiscovered  elements;  thus,  in  columns  III  and  IV, 
when  the  table  was  first  published  the  elements 
gallium  (Ga)  and  germanium  (Ge)  were  unknown, 


172  PllARMACKCTIC    CHEMISTRY. 

Init  by  t'oniparinj^  ihc-  proijcrlics  of  uluminum  and  in- 
dium in  one  case  and  of  silicon  and  tin  in  the  other,  an 
accurate  forecast  of  all  the  chief  properties  of  these 
elements  was  made  and  completely  verified  when  the 
elements  were  isolated. 

There  seems  to  he  some  difficulty  in  finding 
satisfactory  jjlaces  for  the  recent  elements,  argon, 
helium,  neon,  etc. 


17: 


> 

^  1 

q 

Fe  56.      Co  50.      Ni  59 
Ru  102.  Rh  103.  Pd  106 

Os  191.    Ir  193.    Pt  105 

> 

1  ^-!i  s-i   111 

,:s=^-.  Ill 

> 
> 

1  ^  t^f^  1     1  - 

1  0     0     S  "  1      ^  1  ^ 

i  "    "^   ^  -  1     rt  1  1 

> 

'  U      H      N      U        '         ' 

1            '  m     c)^     >-     hJ     >^     H 

. 

q      ■ 

1     f    N    SI     it^'i 

'  pq      U     c«      m               ' 

3 

<^        3         be                   3    , 

CHAPTER  XVII. 
THE   RARE   METALS. 

These  metals  are  of  such  rarity  or  of  so  little  \aluc 
in  pharmacy,  as  to  be  deemed  scarcely  worthy  of  a 
place  in  the  discussion  of  the  several  groups. 

I.  The  following  are  the  rare  metals  of  the  hydro- 
chloric acid  group,  thallium  and  tungsten.  The  group 
reagent  precipitates  them  as  thallous  chlorid  and 
tungstic  acid. 

THALLIUM,  Th,  204,  resembles  lead  in  many 
ways  and  the  alkali  metals  in  some  others.  It  is 
precipitated  as  chlorid,  but  this  chlorid  readily  dis- 
solves in  sulfuric  acid,  forming  soluble  thallous 
suljate.  Thallium  compounds  impart  a  brilliant 
green  to  the  ^amc. 

TUNGSTEN,  W,  184.  The  most  commonly  met 
with  comixnmd  of  tungsten  is  sodium  tungstate, 
which  is  one  of  several  compounds  with  sodium. 
Sodium  metatungstate  is  used  to  render  fabrics 
uninflammable. 

Tungsten  compounds  are  characterized  by  the 
blue  color  given  %vhen  metallic  zinc  is  added  to  its 
solution  and  the  solution  strongly  acidified  icith 
hydrochloric  acid. 

The  rare  metals  oj  group  II  or  the  hydrogen  sul- 
fid  group. 

I.  GOLD,  .\u,  i()7,  and  PLATINUM,  Tt,  194 
These  metals  are  really  not  rare  metals,  since  they 
are  so  well  known  in  a  general  wa\\  but  it  is  not  ollen 
174 


RARE    METALS.  175 

that  the  pharmacy  student  is  called  upon  to  consider 
compounds  containing  them.  Usually  they  are  met 
with  only  as  alloys.  These  metals  are  insoluble  in 
acids,  except  the  nitrohydrochloric  which  yields  their 
chlorids.  Because  of  their  solubility  in  this  acid 
it  received  the  name  "aqua  regia"  (kingwater). 
These  metals  together  with  silver  and  mercury  are 
classed  as  the  "noble  metals."  But  few  simple  salts 
are  known  and  these  are  characterized  by  the  ease 
with  which  they  are  reduced  to  the  metallic  state. 
The  chlorids  of  these  metals  are  precipitated  by 
hydrogen  sultid  or  ammonium  sulfid,  forming  sulfids; 
on  boiling  the  solution  the  gold  comes  down  in  the 
metallic  state.  Both  gold  and  platinum  form 
double  salts  with  the  alkalin  chlorids;  thus  NaCl- 
AuClg;  NaClPtCl,.  Stannous  chlorid  with  a  gold 
solution  gives  a  reddish-brown  to  purple  color  or 
precipitate,  known  as  the  "purple  of  Cassius." 

II.  Four  rare  elements — Iridium,  telluriuw,  sele- 
nium.a.nd  molybdenum  form  sulfids  with  the  group 
reagent  H^S.  They  are  soluble  in  ammonium  sulfid, 
hence  belong  to  the  arsenic  division. 

IRIDIUM,  Ir,  193. 1,  differs  from  platinum  in  not 
being  soluble  in  aqua  regia.  In  general  it  resembles 
platinum. 

TELLURIUM,  Te,  25  (i)  and  SELENIUM,  Se,  78.8, 
are  on  the  border-line  between  nonmetals  and 
metals.  They  so  closely  resemble  sulfur,  as  to  be 
classed  with  the  sulfur  group. 

MOLYBDENUM,  Mo,  96,  is  usually  met  with  as  the 
ammonium    molybdate,  (NHJ2M0O4,  and   is   mostly 


i>6 


PIIAKMACEUTH:    CHEMISTRY 


iiM'd  to  ])ri'(ij)it;it(.'  phosphorus,  with  which  it  forms 
the  yellow,  insoluble  ammonium  phosphomolvbdate. 
Ruthenium,  Ru,  101.6;  Rhodium,  Rh,  103;  Pal- 
ladium, Pd,  106.5,  ^^^  Osmium,  Os,  190.8.  These 
four  elements  belong  to  the  platinum  group — their 
sulfids  are  insoluble  in  ammonium  sulfid.  The 
first  two  are  seldom  met  with,  palladium  and  osmium 
more  frequently.  Osmium,  forming  osmic  acid,  is 
used  in  the  preparation  of  microscopic  sections  of 
animal  tissues.  This  compound  is  really  a  tetroxid, 
OsO^,  or  an  anhydrid.  The  rare  elements  of  the 
ammonium  sulfid  group  may  be  divided  for  con- 
venience into  five  classes,  in  accordance  with  the 
form  in  which  each  is  precipitated.     Taljulatcd  thus: 


II. 


III. 


IV. 


V. 


(a) 
Beryllium 
Be,  9 
Be(OH). 


(n) 

Siandium 

Sc,  43.9 

.Sr(OH), 

(b) 

V  ttrium 

Y,  89 . I 

V(OH)3 

(r) 

Ylt  rhium 

Vb,  173 
I  Yb(OH)3 
I        (d) 
j  Cerium 

Ce,  133 
I  Ce(OH)3 
I        (e) 
Lanthanum 
I  La,  138.2 
La(OH)3 


(a) 

Zirconium 

Zr,  90 . 4 

I  Zr(OH)4 

(b) 
Thorium 
Th,  232 
Th((J>H)4 


(a) 
Titanium 

Ti,  48 
1  HjTiO., 

(b)  ■ 


(a) 
Uranium 
11,239.6 

uos 

(b) 


Tantalum    Indium 
Ta,  1 82. 6    In.  113. 7 
IIjTaO,       InS 


Niobium 
Nh,93.7 
,  H,Nb04 


Thallium 
Th,  204.2 
Th,S 
(d) 

[Vanadium 

I  V,  51 

!  Not  prc- 
linitattd 


RARE    METALS.  177 

Uses. — These  rare  elements  do  not  as  yet  find 
much  application  in  the  arts. 

Zirconium  is  used  in  the  manufacture  of  the  so- 
called  "Welsbach  gas  mantles,"  where  it  assists  in 
the  "incandescence." 

Uranium  is  used  as  a  chemical  reagent. 

Uranium  acetate  finds  considerable  application  in 
the  volumetric  estimation  of  phosphates. 

Cerium  is  found  in  many  minerals,  but  especially 
in  cerite — a  silicate.  Cerium  oxalate  is  its  important 
medicinal  salt,  062(0204)3-1-91120.  Made  by  precipi- 
tating cerous  chlorid  with  ammonium  oxalate.  The 
official  cerium  oxalate  is  not  a  pure  salt,  but  is  a  mix- 
ture of  the  oxalates  of  cerium,  didymium,  lanthanum 
and  other  rare  earths. 

The  rare  elements  of  the  alkalin  group  comprise 
Rubidium,  Rb,  85.3,  and  Cesium,  Cs,  132.6.  These 
possess  almost  identical  characteristics  with  potassium 
and  can  be  detected  only  with  difficulty.  Their  sepa- 
ration is  based  upon  the -comparative  solubility  of 
their  chloro-platinates.  They  play  no  special  part 
in  ordinary  chemistry  or  pharmacy. 


178  PHARMACKUTIC    CHEMISTRY. 

VALENCES  OF  THE  METALS. 


Sym- 
bol 


Valence 
n  "ous" 
com- 
pounds 


Valence 
in  "ic" 
com- 
pounds 


Atomic 
weights 


Ag 
Pb 
Hg' 

As 
Sb 
Sn 
Bi 
Cu 

?r 

Fe 
Co 

Ni 
Mn 
Zn 
Al 
Cr 
Ca 
Sr 
Ba 
Mg 
Li 
Na 
K 
(NHJ 


Silver 

Lead 

Mercury  (ous) 

Arsenic 

Antimony  .... 

Tin 

Bismuth 

Copper 

Mercury  (ic). . 
Cadmium  .... 

j  ron 

Cobalt 

Nickel 

Manganese .  .  . 

Zinc 

A]uminum  .  .  . 
Chromium  .    . 

Calcium 

Strontium.  .  .  . 

Barium 

Magnesium. .  . 

Lithium 

Sodium 

Potassium. .  .  . 
Ammonium  .  . 


3 
3 
3 
3 
2 

3 

4,6 

2 


107. 1 

205 -3 

198.3 

74-4 

II9-3 

118. 1 

206. 9 

63.1 

198.3 

III. 6 

55-5 

58. 5 

58.3 

54-6 

64.9 

26.9 

51 -7 
39-8 
86.9 
136.4 
24.  T 
6.9 
22.8 
38.8 


THE  IONIC  THEORY.— When  solutions  are  sub- 
jected to  tlie  action  of  an  electric  current,  a  decom- 
position known  as  electrolysis  takes  ])lace,  and  tlie 
minute  particles  separated,  called  "ions,"  are  at- 
tracted to  the  positive  pole,  called  the  electric  aiiodc, 
and  to  the  negative  pole,  called  tJie  cathode.  The 
ions  attracted  to  the  anode,  positiw  pole,  iire  eUrIro- 


VALENCE.  179 

positive  (  +  ),  and  are  called  anions.  Those  col- 
lecting at  the  negative  pole  ( — ),  or  cathode,  are  electro- 
negative, and  called  cathions.  As  a  general  rule,  the 
metallic  elements  form  positive  ions  and  the  non- 
metallic,  negative  ions.  The  positive  ions  attract  the 
negative  ions  and  repell  the  positive,  the  inverse  being 
true  for  the  negative  ions. .  The  polarity  of  an  ion 
may,  however,  be  changed  by  the  inducing  action  of 
other  ions. 

Valence. — By  analysis  of  a  great  number  of  hydro- 
gen compounds,  it  has  been  determined  that  dif- 
ferent elements  combine  with  it  in  definite  propor- 
tions, but  that  these  proportions  vary  in  different 
compounds  and  with  different  elements.  It  was 
found  that  chlorin  unites  with  hydrogen  in  propor- 
tion to  its  atomic  weight.  Thus:  35.4  parts  by 
weight  of  chlorin  unite  with  i  part  by  weight  of 
hydrogen.  But  oxygen  unites  in  half  its  atomic 
weight,  or  requires  two  atoms  of  hydrogen  to  one 
atom  of  oxygen.  Nitrogen  similarly  requires  three 
atoms  of  hydrogen;  carbon,  four  atoms,  etc.  This 
power  of  combination  is  known  as  valence,  and  the 
valence  of  any  element  depends  upon  the  number  of 
atoms  of  hydrogen  or  its  equivalent  that  the  element 
will  unite  with  or  replace  in  a  compound. 

PHYSICAL    CHEMISTRY  AND  ELECTRO- 
CHEMISTRY. 

At  the  present  time  two  distinctive  and  very  im- 
portant branches  of  chemistry  are  receiving  much 
consideration  and  study;  these  are  physical  chemistry 


l8o  IMIAKMACErilC    CUEMISTK V. 

iind  eUrtrofliciiiislry.  Tliese  Ijranchcs  make  use  of 
the  i)hvsical  constants  to  determine  the  characteristics, 
properties,  etc.,  of  any  element  or  compound.  Close 
study  is  made  of  the  effects  of  heat  and  cold,  light, 
color,  pressure,  temperature  and  their  changes,  polari- 
metric  properties,  etc.,  are  all  taken  into  account. 
In  electrochemistry  the  distinctive  properties  of  the 
electric  current  are  made  use  of  and  api)lied  in  the 
arts.  Thus,  union  among  the  gases  may  readily  l)c 
l)n)Uglit  al)()ut  l)y  llie  action  of  an  induction  sj)ark. 

Bv  passing  the  galvanic  current,  however,  such 
union  of  gas  may  again  he  resolved  into  its  con- 
stituents. We  can,  therefore,  employ  the  electric  cur- 
rent for  i)oth  synthesis  and  analysis.  Decomposi- 
tion of  compounds  by  electric  current  is  called  electro- 
Ivtic;  the  operation,  electrolysis.  Thus,  a  sohilion  of 
zinc  sulfate  may  l)e  electrolyzed  according  lo  tlie 
following  equation:  ZnS()4  +  (electric  current)  = 
Zn  (at  cathode)  +  SO^  (at  anode).  The  ele(troi)osi- 
live  metallic  zinc  is  deposited  at  the  negali\e  pok' 
(cathode)  and  the  electronegative  radical  (SO,)  sepa- 
rates at  the  positive  pole  (anode).  The  substance  to  be 
electrolyzed  must  be  in  a  gaseous,  licjuid.or  fused  con- 
dition, and  is  known  as  electrolyte.  The  particles  into 
which  a  salt  will  chHiroly/.e  are  called  "io)is'\  thu>, 
zinc  sulfate  is  lomposed  of  two  ions— Zn  and  the 
(SO4)  radical. 

Application  0/  the  electric  current  is  made  use  of  in 
chemical  analysis  for  depositing  the  metals,  which  can 
l)e  done  quantitatively,  and  in  e!ectrotyi)ing-  or  (h-- 
])ositing  of  a  la\cr  of  copper  over  moulds  or  tyju — 


I  UNIVERSITY  J) 

^  == ELECTRICITY.  l8l 

for  the  purpose  of  reproducing  the  same.  Electro- 
types are  made  use  of  in  the  printing  of  books,  maga- 
zines, maps,  etc.,  and  are  made  from  the  forms  set  up 
by  the  printer.  Such  electrotypes  can  be  preserved 
for  subsequent  use. 

Electroplating  is  the  process  of  depositing  electro- 
lytically  one  metal  upon  another — usually  a  cheaper 
one. 

Eleclrxity  is  also  used  in  the  refining  oj  metals, 
preparation  oi  caustic  alkalis,  chlorates,  hypochlorites, 
white  lead,  Prussian  blue,  etc.,  also  many  organic 
compounds. 


CHAPTER  XVIII. 

CHEMICAL    NOMENCLATURE    AND    CHEMICAL 
FORMULAS. 

Berzelius  (1815)  proposed  the  short-hand  form  of 
chemical  language;  since  that  time,  we  are  employing 
a  system  of  symbols  and  symbolic  formulas  for  the 
elements  and  compounds. 

In  Chapter  II  simple  definitions  were  given  for 
the  acids,  salts,  etc.  It  is  difficult — almost  impossi- 
ble— to  give  concise  definitions  in  chemistry. 

BASE  is  a  term  properly  appHed  to  a  combination 
of  a  basic  oxid  with  water,  thus,  Na^O  +  HjO  = 
2NaOH,  called  sodium  hydroxid,  hydrate,  or  simply 
soda;  CaO  +  U^O  =  Ca  (OH),,  called  calcium 
hydroxid,  hydrate,  etc.,  are  bases. 

Sodium  oxid,  Na,©,  calcium  oxid,  CaO,  are  incor- 
rectly termed  bases. 

ACID  (1)  is  a  com])()und  of  an  electronegative 
element  or  radical  with  hydrogen,  part  or  all  of  which 
can  be  exchanged  for  an  electropositive  clement 
without  forming  a  base.  (2)  An  acid  is  a  salt  of 
hydrogen.  An  acid  can  be  produced  by  combining 
an  anhydrid  with  water;  thus,  N2O5  -f  HjO  = 
2HNO3  =  nitric  acid.  Elements  like  S,  CI,  Br,  1, 
etc.,  combine  with  hydrogen  directly,  forming  acids; 
thus,  sulfur  i)roduces  US  =  hydrosulfuric  acid; 
iodin  produces  HI  =  hydriodic  acid,  etc. 
182 


NOMENCLATURE.  1 83 

SALT  is  hard  to  define  concisely:  (i)  Salt  is  an 
acid  in  which  the  hydrogen  has  been  replaced  either 
in  part  or  entirely  by  a  metal  or  radical.  (2)  Salt  is  a 
combination  of  an  anhydrid  with  a  basic  oxid;  thus, 
Na.O  +  N2O5  =  2NaN03.  Salts  may  be  normal, 
acid  or  basic. 

ANHYDRID  is  an  acid  oxid.  It  is  the  part  of  an 
acid  remaining  after  the  removal  of  the  elements  of 
water.  Anhydrids  combine  with  water  to  form  acids. 
2HNO3  —  H2O  =  N2O5  =  nitric  (oxid)  anhydrid. 

nitric  acid 

H2SO4  —  H2O  =  SO3  =  sulfuric  (oxid)  anhydrid. 

sulfuric  acid 

With  water  these  anhydrids  re-form  the  acid:  SO3 
+  H.O  =  H.,SO,  =  sulfuric  acid. 

EMPIRIC  FORMULA  is  the  expression  of  the 
simplest  ratio  of  the  elements  composing  a  com- 
pound. Thus,  Fe03H3  is  the  empiric  formula  for 
ferric  hydroxid,  and  CH^O,  the  empiric  formula  for 
acetic  acid. 

MOLECULAR  FORMULA  is  the  expression  of 
the  actual  number  of  atoms  of  each  element  in  a 
molecule.  It  may  be  identical  with  the  empiric 
formula  or  a  multiple  of  it;  thus,  CjH^Oj  is  the 
molecular  formula  for  acetic  acid. 

TYPE  FORMULA  is  a  molecular  formula  arranged 
after  one  of  the  three  common  types: 

/H 
H— O— H  ->  H— CI  -^  N— H 

water  type  hydrochloric  \H 

acid  type         r- 

ammonia 
type 

ISOMERISM  is  a  term  designating  bodies  having 


184  PHARMACEUTIC    CHEMISTRY. 

the  same  cnipirit-  f(jrmuhis  but  different  proj)erties. 
Isomerism  applies  to  compounds,  while  to  elements 
is  applied  the  term — 

ALLOTROPISM,  a  term  designating  those  modifiT 
cations  of  an  element  which  present  different 
physical  properties.  Thus,  phosphorus  exists  in 
two  modifications:  the  yellow,  which  is  inflammable 
and  poisonous,  and  the  red,  which  is  noninflam- 
mable  and  nonpoisonous.  Carbon  exists  in  three 
allotropic  forms:  diamond,  graphite  and  coal. 

POLYMERISM  applies  to  compounds  having  the 
same  empiric  but  different  molecular  formulas; 
thus,  aldehyd  has  the  formula  CjH^O;  its  polymer 
paraldehyd  has  the  formula  CgHjjO^;  it  is  derived 
by  multiplying  the  aldehyd  formula  by  3. 

HOMOLOGOUS  SERIES  is  a  group  of  substances 
with  similar  projierties,  whose  molecular  weights 
have  a  common  difference;  thus,  the  paraffin  series 
differ  by  CHj  group  from  one  another  and  l)y  14  in 
their  molecular  weights. 

ISOLOGOUS  SERIES  in  organic  chemistr}-  ap- 
plies to  substances  differing  by  H^;  thus: 

C2Hg=  ethane;  CjH^  =  ethylene;  C^H-,  =  acety- 
lene, are  isologous  compounds. 

AMORPHOUS  is  api)licd  to  ])odics  incai^nble  of 
crystallization. 

MONOMORPHOUS,  ca])able  of  crystallizing  in  one 
form. 

DIMORPHOUS,  crxstallizing  in  two  forms,  as 
sulfur. 

TRIMORPHOUS  and  POLYMORPHOUS  are  terms 


NOMENCLATURE.  1 85 

applied  to  bodies  crystallizing  in  three  forms  and 
many  forms,  respectively. 

ISOMORPHOUS  is  u  term  applied  to  dit^'ercnt 
jjodies  crystallizing  in  the  same  form. 

ALLOY  is  a  mixture  of  two  or  more  metals. 

AMALGAM  is  a  term  applied  to  the  union  of  a  metal 
with  mercury.      (Hg  does  not  amalgamate  Fe  or  P.) 

EFFLORESCENT  substances  are  those  which  lose 
their  water  of  crystallization  at  ordinary  tempera- 
tures (Na^COg). 

DELIQUESCENT  substances  are  those  which 
absorb  sufficient  water  from  air  to  form  a  solution  at 
ordinary  temperatures  (KOH). 


PHARMACEUTIC    CHEMISTRY 


EQUATIONS.  187 

EQUATION  WRITING. 

A   Sludy  oj  Chemical  Changes. 

Under  certain  condiliDns  all  material  bodies  may 
undergo  certain  changes.  When  these  changes  occur 
within  the  molecular  structure  of  these  bodies,  they 
may  be  said  to  be  "chemical  changes."  Thus, 
when  two  bodies  upon  coming  in  contact  exert  an 
action  on  one  another,  such  action  is  called  a  reaction. 
A  body  which  when  added  to  another  body  causes 
such  a  change  is  called  a  reagent;  the  results  oj  the 
reaction  are  called  products,  and  the  reactive  bodies 
are  termed  factors. 

Thus,  when  metalUc  zinc  is  brought  in  contact 
with  sulfuric  acid,  zinc  sulfate  is  formed  and  hydro- 
gen gas  is  given  off.  Thus,  zinc  is  the  reactive  body, 
H2SO4  the  reagent,  zinc  sulfate  and  hydrogen  gas  are 
the  products,  while  zinc  and  the  acid  have  served  as 
the  factors  in  the  reaction. 

Equations  are  representations  of  chemical  reactions 
by  means  of  symbols  and  algebraic  signs. 

In  writing  equations,  the  symbolic  formulas  of  the 
factors,  united  by  the  plus  sign  (  +  )  are  written  to 
the  left  of  the  equality  sign  (  =  ),  while  the  symbolic 
formulas  of  the  products,  also  united  by  the  plus  (  +  ) 
sign,  are  written  to  the  right  of  the  equality  sign. 

The  reaction  between  zinc  and  sulfuric  acid  is 
illustrated  by  the  following  equation: 

The  factors:  The  products: 


Zn 


+  H2SO,  =        ZnSOJ+H 


sulfuric  zinc     jhydrogen 

acid  sulfate  | 


lOS  PIIARM ACEITIC    CIIKMISTRY. 

In  another  chapter  it  has  been  slated  that  syiuhols 
represent  definile  weights.  Equations  can  therefore 
l)e  easily  reduced  to  figures.  Thus,  atomic  weights 
of  the  elements  entering  in  the  above  equa 
tion  are  zinc  =  65;  H._,SC)^  e([uals  H  =  2,  S  =  32, 
0   =   16. 

We  had,  therefore,  65  parts  of  zinc  reacting  with  98 
parts  of  sulfuric  acid,  which  produced  161  parts  of 
zinc  sulfate  and  2  parts  of  hydrogen.  If  we  examine 
further  into  this  reaction,  we  will  see  that  the  total 
atomic  weight  of  the  factors  to  the  left  of  the  sign  of 
equality  is  163,  and  that  those  of  the  product  to  the 
right  is  found  to  be  the  same.  In  a  correctly  written 
ecjuation  the  sum-total  of  the  atomic  weights  on  both 
sides  of  the  sign  of  equality  must  balance  and  so 
must  the  number  of  atoms  on  each  side.  The  fol- 
lowing should  be  remembered  while  constructing 
equations: 

(i)  That  positive  atoms  unite  only  with  negatives, 
and  not  with  postives. 

(2)  That  the  valences  of  the  atoms  and  radicals 
must  in  all  cases  he  satisfied  (saturated). 

(3)  That  the  members  of  an  equation  must  repre- 
sent whole  molecules. 

(4)  That  compound  radicals  usuall)-  remain  as 
such  in  the  products. 

(5)  That  acids  and  bases  neutralize  each  other  and 
therefore  cannot  exist  in  the  same  solution. 

(6)  That  an  equation  nmst  balance  before  it  can  be 
regarded  as  completely  representing  a  chemical 
change. 


EQUATIONS.  109 

A  thorough  knowledge  of  the  rules  of  writing 
chemical  equations  is  of  absolute  importance,  and 
the  student  should  pay  most  careful  attention  to 
them.  By  the  method  of  presentation  given  below 
the  student  can  quickly  grasp  the  gist  of  the  subject. 
The  simpler  equations  are  discussed  first,  followed  by 
the  more  complex  and  difficult  ones. 

Equations  may  he  divided  into  jour  classes: 
(0  Analytic  Equations.— Under  this  heading  are 
included  those  equations  which  represent  the  split- 
ting of  more  complex  compounds  into  simpler  ones. 
Thus,  when  potassium  chlorate  is  heated,  it  splits  up 
into  potassium  chlorid  and  oxygen.  This  can  serve 
as  a  typical  equation  representing  analysis  (from 
ana,  up;  lysis,  separation): 

(./)       2KCIO,  =  2KCI  +  30^ 

potassium  =         potassium         +         oxygen 

chlorate  chlorid 

Mercuric  oxid  splits  into  mercury  and  oxygen: 

{b)         2HgO  =  Hg3  +         _^___ 

mercuric  =  mercury  +         oxygen 

oxid 

By  means  of  electricity,  water  can  be  decomposed 
into  its  elements — hydrogen  and  oxygen: 

(c)         2H,0  =  JH_4  _  ,        +  Q. 

water  =  hydrogen         -f         oxygen 

(2)  Synthetic  Equations.— Under  this  head  belong 
equations  representing  the  union  of  elements  to 
form  compounds,  also  the  union  of  simpler  com- 
pounds to  form  more  complex  ones.  A  type  of 
synthetic     (from     syn,     together;    thesis,     bringing) 


igo  PHARMACEUTIC    CHEMISTRY. 

reaction  is  tiie  following,  which  represents  the  forma- 
tion of  water  from  its  elements: 

(a)  2H,  4-  O,  =  2H,0 

The  formation  of  iron  sulfid  from  its  elements: 

(b)  2Fe_  +  S.  =  2FeS 
iron               -f             sulfur            =        iron  sulfid 

The  formation  of  sulfur  dioxid  in  the  process  of 
burning  sulfur  in  the  air;  the  sulfur  vapor  combining 
with  the  oxygen  of  the  air: 

(c)  S,  +  20^  =  2SO^ 

sulfur  +  oxygen  =      sulfur  dioxid 

(3)  Single  Decomposition  Equations. — Under  this 
heading  are  included  those  reactions  in  which  one 
of  the  factors  is  split,  the  other  remaining  intact. 
The  action  of  hydrochloric  acid  on  zinc,  in  which  the 
acid  splits  into  its  elements  (hydrogen  and  chlorin), 
serves  as  a  type : 

(a)  Zn       +   _jHCl  =        ZnCl,  +        H, 

zinc     +    hydrochloric   =zinc  chlorid       +  hydrogen 

acid 

When  dilute  sulfuric  acid  acts  on  iron,  iron  sulfate 
(ferrous  sulfate)  is  formed  and  hydrogen  is  set  free. 
(The  iron  sulfate  may  be  called  a  product,  while  the 
hydrogen  in  such  operation  is  usually  termed  a 
by-product.) 

(b)  2Fe       +        2H,S04         =        2FeSo4      +        2H, 
iron      +     sulfuric  acid     =    iron  sulfate  +  hydrogen 

When  iron  hydroxid  is  heated  in  a  stream  of 
hydrogen,  reduced  iron  (ferrum  reductum  U.  S.  P.) 
is  formed: 

(f)      2Fe(OH),      +_  3H,         =         Fe^      -f       6H,0 
ferric  hydroxid  +  hydrogen  =        iron       +        water 


EQUATIONS.  191 

(4)  Double  Decomposition  Equations. — Under  this 
heading  belong  those  equations  in  which  both  the 
factors  suffer  decomposition.  Thus,  in  the  action  of 
hydrochloric  acid  on  potassium  hydroxid,  potassium 
chlorid  and  water  are  formed,  showing  that  both  the 
acid  and  the  potash  were  decomposed.  The  following 
may  serve  as  a  type  for  the  fourth  class. 

(a)       KOH      +  HCl       =       KCl         +         H^O 

potassium  +  hydrochloric  =   potassium  +         water  . 
hydroxid  acid  chlorid 

When  hydrochloric  acid  acts  on  zinc  oxid,  zinc 
chlorid  and  water  are  formed: 

(6)      ZnO     +  2HCI  =         ZnCU  +     H^O 

zinc  oxid  +  ac.  hydrochloric    =    zinc  chlorid    +    water 

When  hydrochloric  acid  acts  on  ferric  oxid,  ferric 
chlorid  and  water  are  formed: 

(c)      Fe.03     +  6HC1  =      2FeCl3       +  3H.O 

ferric  oxid  +  ac.  hydrochloric  =  ferric  chlorid  +  water 

Rules  for  writing  Equations. — All  of  the  commoner 
equations  belong  to  one  of  the  four  classes  just  dis- 
cussed. The  seven  rules  following  embrace  all  of 
the  reactions  common  to  pharmaceutic  procedure. 
It  will  be  observed  that  most  of  the  reactions  belong 
to  the  fourth  class  (double  decomposition) .  Students 
will  do  well  to  memorize  these  rules  correctly, 
and  frequently  practice  equation  writing.  Equation 
writing  is  of  inestimable  value  in  quickly  grasping 
chemical  changes  and  theories. 

Rule  I. — Whenever  a  hydroxid  of  a  metal  is  dis- 


192  PHARMACEUTIC    CHEMISTRY. 

solved  in  an  acid,  a  salt  oj  the  metal  and  water  are 
produced;  thus: 

(i) 

KHO  +        HCl         =         KCl         +        H,0 

potassium  hydrochloric       pcjtassium               water 

hydrate  acid                  chlorid 

(2) 


2KHO 

+      H,S04       = 

K.SO^ 

+ 

2H,0 

potassium 
hydrate 

sulfuric 
acid 

potassium 
sulfate 

water 

Ca(HO), 

+       2  HCl 

CaCl, 

+ 

2H,0 

calcium 
hydrate 

hydrochloric 
acid 

calcium 
chlorid 

water 

2Fe(HO)3 

+        6HC1       = 

2FeCl,, 

+ 

6H,0 

ferric 
hvdratc 

hydrochloric 
acid 

ferric 
chlorid 

water 

(.s) 


(4) 


Zn(HO),    +       H,S04       =       ZnS04      +       zH^O 
zinc  sulfuric  zinc  water 

hydrate  ai  id  sulfate 

Rule  II. — Whenever  an  oxid  oj  a  metal  is  dissolved 
in  an  acid,  a  salt  oj  the  metal  and  wat^r  are  produced 
(the  only  excei)ti()ns  beiiiff  the  higher  oxids  of  the 
metals);  thus: 

(i) 


(2) 


CaO 

+ 

2HCI 

CaCl. 

+ 

H,0 

calcium 
oxid 

•i) 

'drochloric 
acid 

calcium 
chlorid 

water 

BaO 

+ 

2  HCl 

liaCl, 
barium 
chlorid 

+   _ 

H,() 

liarium 
oxid 

•dnxhloric 
arid 

water 

EQUATIONS.        " 

^ 

Fe,0, 

+ 

6HC1 

^ 

2FeCl3 

4- 

3H^O 

ferric 

hydrochloric 

ferric 

water 

oxid 

acid 

chlorid 

MgO 

+ 

H,S04 

= 

MgS04 

+ 

H,0 

magnesium 

sulfuric 

magnesium 

water 

oxid 

acid 

sulfate 

CuO 

+ 

2HNO3 

= 

Cu(NO,0, 

+ 

H,0 

copper 

nitric 

copper 

water 

oxid 

acid 

nitrate 

PbO 

+ 

2HNO3 

_ 

Pb(NO,). 

+ 

H,0 

lead 

nitric 

lead 

water 

oxid 

acid 

nitrate 

Sb^O,, 

+ 

6HC1 

= 

2SbCl3 

+ 

3H.O 

antimony 

h 

ydrochloric 

antimony 

water 

oxid 

acid 

chlorid 

(3) 


(4) 


(5) 


(6) 


(7) 


Rule  III. — Whenever  a  carbonate  oj  a  metal  is 
dissolved  in  an  acid,  a  salt  oj  the  metal,  water  and 
carbon  dioxid  {carbonic-acid  gas)  are  produced,  the 
latter  is  given  off.  In  equations  the  radical  of  the 
carbonates  (€0^)  splits  up  into  CO^  and  O,  the  former 
escaping,  the  latter  uniting  with  the  H^  to  form  ivater; 
thus : 


(i) 


(2) 


CaCO,, 

+ 

2HNO3     = 

Ca(N03).  +    CO.     + 

H,0 

calcium 
carbonate 

nitric 
acid 

calcium         carbon 
nitrate           dioxid 

water 

K.COj 

+ 

2HCI       = 

2KCI       +    CO3    + 

H.O 

potassium 
carbonate 

hydrothloric 
acid 

potassium       carbon 
chlorid           dioxid 

water 

194  PHARMACEUTIC    CHEMISTRY. 

Na,C03    +     H,S04     =    Na.S04    +    CO,    +    H,0 
sodium  sulfuric  sodium  carbon        water 

carbonate  acid  sulfate  dioxid 

Rule  IV. — Whenever  a  metal  is  dissolird  in 
hydrochloric  acid  or  in  aqua  regia,  a  chlorid  oj  the 
metal  is  akcays  formed  and  hydrogen  given  of];  thus: 

(0 


(2) 


Rule  V. — Whenever  a  metal  is  dissolved  in  dilute 
sulfuric  acid,  a  siiljate  oj  the  metal  is  ahvays  formed 
and  hydrogen  given  off ;  thus: 

Zn  +       H,S04       =       ZnS04      + ^H^ 

(2) 


Fe, 
iron 

+        4HCI         = 

hydrochlor'c 

acid 

2FeCl. 
ferrous 
chlorid 

hydrogen 

Pb 

+        2HCI 

PbCU 

+          H, 

lead 

hydrochloric 
acid 

lead 
chlorid 

hydrogen 

zinc 

sulfuric 
acid 

zinc 
sulfate 

hydrogen 

2Fe 

+ 

2H,S04        = 

=       2FeS04 

+            2H, 

iron 

sulfuric 
acid 

ferrous 
sulfate  ■ 

hydrogen 

Rule  VI. — Whenever  a  metal  is  dissolved  i)i  strong 
sulfuric  acid,  a  suljate  oj  the  metal  and  water  are  formed, 
gaseous  sulfur  dioxid  {SO^)  evolved.  The  sulfates 
usually  made  by  the  action  of  strong  sulfuric  acid  on  the 
metals  are  mercury,  copper  and  silver  sulfates ;  thus: 

(0 


Hk 

+ 

2H,S04     = 

=      HgSOj     +     ^0,     +  2H/:) 

mercury 

sulfuric 
acid 

nuTcuric          sulfur        water 
sulfate            dioxid 

(2) 


(3) 


EQUATIONS. 

195 

__2CU 

copper 

+ 

4H.SO4     = 
sulfuric 
acid 

=     2CUSO4 
copper 
sulfate 

+  2SO.  +  4H.O 
sulfur  water 
dioxid 

2Ag 

silver 

+ 

2H,S04      = 

sulfuric 
acid 

=     Ag,S04 
silver 

sulfate 

+  SO-  4-  2H-O 
sulfur  water 
dioxid 

It  should  l)e  noticed  that  twice  the  required 
quantity  of  the  acid  is  taken  to  furnish  VSO4  for  the 
sulfate,  the  extra  SO4  spHtting  up  into  SO2  and  O2. 
The  former  escapes  and  the  latter  unites  with  the 
hydrogen  to  form  water. 

Rule  VII. — The  ordinary    metals    {excepting   tin, 
antimony,  arsenic  and  zinc),  when  acted  upon  uith 
slightly  diluted  nitric  acid,  form   metallic  nitrates  and 
evolve  nitric  oxid  (NO);  thus: 
(i) 


(2) 


(3) 


(4) 


(5) 


6Ag 

+ 

8HNO, 

=    6AgN03 

+    2NO    +  4H.O 

silver 

nitric 
acid 

silver 
nitrate 

nitrogen       water 
oxid 

3Pb 

+ 

8HNO3 

=  3Pb(NO,). 

+    2NO    +  4H2O 

lead 

nitric 
acid 

lead 
nitrate 

nitrogen  water 
oxid 

3Hg 

+ 

8HNO3 

=  3Hg(N03), 

+    2X0    +  4H20 

mercury 

nitric 
add 

mercuric 
nitrate 

nitrogen  watf-r 
oxid 

3Cu 

+ 

8HNO3 
nitric 
acid 

=  3Cu(N03). 
copper 
nitrate 

+    2NO    +  4H,0 

copper 

nitrogen  water 
oxid 

2Bi 

+ 

8HNO3 

=    2Bi(N03)3 

+    2NO    +  4H20 

bismuth 

nitric 
acid 

bismuth 
nitrate 

nitrogen  water 
o.xid 

196  PHARMACEUTIC    CHEMISTRY. 

It  should  he  noticed  that  eight  equivalents  of  nitric 
acid  arc  employed  for  every  six  eqtiivalents  oj  the 
metal.  This  is  true  of  all  the  reactions  of  HNO., 
upon  the  metals;  the  by-products  always  being  2 
molecules  of  nitric  oxid  and  4  of  water. 

STOICHIOMETRY.— It  is  often  necessary  to  con- 
sider, by  means  of  figures,  the  relation  of  the  atoms 
in  a  molecule,  or  of  molecules  in  a  compound;  a'so 
to  determine  percentage  composition,  the  weight  of 
certain  volumes,  etc.  For  this  purpose  stoichiometry, 
or  "chemical  arithmetic,"  is  made  use  of.  All  cal- 
culations in  which  use  can  be  made  of  atomic  weights 
and  vo'umes  are  included  in  this  class. 

As  stated,  every  element  has  its  atomic  weight,  and 
every  molecule  and  compound,  therefore,  has  its 
value  expressible  in  figures. 

As  already  shown,  all  chemical  changes  take  p'are 
between  definite  amounts  of  substance,  and  a  chemical 
equation  expresses  the  amount  of  matter  taking  ])art 
in  it;  thus,  a  reaction  may  be  written: 

H,S04  +  2NaOH  =  2H2O  -f  Na^SO,. 
98  +  2(40)       =  2(18)  +142. 

The  lower  figures  of  the  equation  represent  the 
quantities  that  take  part  in  the  reaction  and  express 
molecular  weights. 

'  The  percentage  of  any  molecule  or  atoms  may  be 
easily  determined  by  comparing  the  quantitx  of  the 
on(>  desired  with  the  total,  on  fhel)asisof  100.  'I'lui^, 
in  our  reaction  just  stated,  if  the  amount  of  sodium 
sulfate  produced  is  desired  in  i)ercentage,  the  pro- 
portion would  be  142  :  178  :  :  x  :  100. 


STOICHIOMETRY.  197 

The  same  process  of  calculation  would  give  us  any 
factor ;  thus,  if  the  percentage  of  sodium  as  an  element 
were  desired,  the  proportion  becomes 
2(23)  :  178  :  :  X  :  loo. 

Any  ofher  modification  may  be  readily  deduced. 
Care  must  be  taken  that  the  proper  atomic  weight,  or 
multiple  of  it,  be  used  in  both  reagent  and  product. 

In  the  example  given,  two  molecules  of  sodium 
hydrate  were  required  to  form  one  molecule  of 
sodium  sulfate,  and  twice  the  atomic  weight  of 
sodium  entered  into  both  factors. 

If  the  problem  had  been,  how  much  sodium  sulfate 
would  be  obtained  from  lo  grams  of  sodium  hydrate, 
the  proportion  would  remain  the  same,  substituting 
10  for  100.  The  answer  would  then  be  in  grams 
instead  of  in  per  cent. 

Exactly  the  same  calculation  is  employed  with  a 
single  molecule  as  in  equations;  thus,  if  the  amount  of 
sodium  present  in  lo  grams  of  sodium  sulfate  were 
desired,  the  proportion  would  be 

Na2S04  =  Na,  +  S  +  0„  or   (46  +  32    +   64) 
46  :   142  :  :  X  :  10,  etc. 
Modifications  of  this  may  be  readily  deduced. 

If  volumes  instead  of  weights  came  into  the 
problem,  the  proportion  is  still  the  same,  but  each 
molecular  formula  represents  two  volumes,  since, 
as  previously  stated,  molecular  weight  is  twice  that  of 
density,  which,  in  turn,  represents  but  one,  and  by 
considering  each  molecule  as  twice  that  stated, 
direct  calculation  may  be  made.  Example:  How 
much  carbon  dioxid  can  be  made  by  burning  one 


198  PIIARMACKUTIC    CHEMISTRY.     ' 

liter  of  carhon  monoxid?  The  reaction  (CO)2 
+  O,  =  (CO,),  read  4  vol.  (CO)  +  2  vol.  (O,)  = 
4  vol.  (CO,)  and  4:  4  :  :  i  :  .x.  .x  =  i.  i  liter  of  CO, 
produced. 

If  the  relation  of  weight  to  volume  or  I'ire  versa  is 
desired,  divide  the  weight  of  the  gas  by  its  weight  per 
liter,  the  quotient  will  be  the  numberof  liters;  or  multi- 
plying the  number  of  liters  by  the  weight  per  liter  gives 
the  weight  of  the  given  volume.  The  original  weight 
or  volume  is  determined  as  stated  in  the  last  two 
proportions  respectively.  Influence  of  temperature 
and  pre  isure  on  gas  volumes  enter  the  calculations: 

According  to  Boyle's  law,  the  volume  of  any  gas 
var'es  inversely  as  the  pressure,  and  its  density  directly 
as  the  pressure;  hence,  gas  volume  changes  with  the 
baometric  pressure.  Normal  barometric  pressure 
is  760  mm.  of  mercury,  the  factor  being,  therefore, 
760. 

Similarly,  all  gases  vary  directly  as  the  tempera- 
ture. Absolute  zero  is  taken  as  — 273°  C,  and  it  is 
claimed,  therefore,  that  a  gas  volume  increases  ^i^  of 
its  volume  for  each  degree  increase  in  temperature 
above  0°  C.  In  order  to  correct  a  gas  volume,  there- 
fore, to  standard  conditions,  the  following  procedure 
may  be  followed:  The  formula 


y 


VP 


760  X  I  -I-  (.003661), 

in  which  \''  =  desired  volume;  V  =  stated  volume; 
p=  barometric  reading;  760  =  normal  barometric 
reading;  i  =  normal  temjjerature,  and  .oo366  =  faclor 
^i-^;  t  =  stated  temperature,  is  used: 


STOICHIOMETRY.  igg 

Example:  What  would  be  the  normal  volume  of  a 
gas  whose  volume,  at  42°  C.  and  with  barometric  read- 
ing 732,  was  976  cubic  centimeters? 

Substituting  in  the  formula  we  have: 

V  =  976  X7H2 ^   7I44.S2 

760X  I  +  (.00366  X42).,     876.827. 

Ans.  =814.7  c.c.  at  0°  C. 

Modifications  of  this  may  be  easily  deduced  bv 
transposition  of  factors.  Very  many  other  uses  may 
be  made  of  stoichiometryand  mathematics  in  chemis- 
try, but  a  full  disscusion  would  require  a  volume  in 
itself,  and  those  given  are  but  the  foundation  for 
manv  others. 


PHARMACEUTIC    CHEMISTRY. 

PART  II. 

ORGANIC  CHEMISTRY. 

CHAPTER  XIX. 

INTRODUCTION. 

The  compounds  of  carljon  with  other  elements, 
such  as  hydrogen  and  oxygen,  are  so  numerous  that 
it  is  necessary  to  devote  to  them  a  special  part  of  the 
study  of  chemistry,  namely,  "organic  chemistry." 
Berzelius  (1818)  defined  organic  chemistry  as  the 
chemistry  of  bodies  formed  under  the  influence  of 
life.  When,  however,  Woehler,  in  1828,  in  an  en- 
deavor to  evaporate  an  aqueous  solution  of  ammo- 
nium cyanate,  found  the  residue  composed  of  a  sub- 
stance different  from  ammonium  cyanate,  namely 
urea,  the  theory  that  "vital  force  "  was  necessary  to 
|)roduce  these  compounds  became  untenable.  It  was 
found  that  they  could  be  produced  synthetically  in 
the  laboratory  of  the  chemist,  and  the  original  belief 
that  organic  substances  could  only  be  produced  by 
animal  or  vegetable  organism  was  found  to  be  wrong, 
and  a  new  definition  for  organic  chemistry  had  to  be 
sought.  Liebig  (1832)  defined  the  science  as  the 
"chemistry  of  compound  radicals."  But,  whereas 
201 


202  I'HARMACEUTIC    CHEMISTRY. 

almost  any  molecule  with  more  than  two  atoms  may 
be  supi)osed  to  contain  a  compound  radical,  that 
definition,  it  will  be  seen,  is  inaccurate;  and,  besides, 
there  are  many  inorganic  compounds  which  also  con- 
tain compound  radicals,  thus,  NH^,  NO3,  SO4,  etc. 

Since  carbonic  oxid,  carbonic  sulfid,  carbonic  acid 
and  their  salts  are  usually  excluded  from  works  on 
organic  chemistry  and  studied  in  conjunction  with 
the  inorganic  compounds,  as  containing  incom- 
bustible carbon,  it  will  be  seen  that  the  present  defini- 
tion is  most  probably  correct,  although  by  some  it  is 
claimed  to  be  too  broad. 

Organic  chemistry  is  now  defined  as  the  study  of 
the  carbon  compounds. 

Thus,  we  have  seen  that  the  discovery  of  urea 
in  1828  marked  the  rise  of  true  organic  chemistry,  and 
since  then  over  one  hundred  thousand  organic  com- 
pounds have  been  prepared  synthetically  from  carbon 
and  the  inorganic  elements  in  the  chemist's  labora- 
tory, duplicating  many  of  nature's  own  products. 
It  is  safe  to  assume  that  every  natural  product  will  be 
duplicated  in  the  laboratory,  and,  indeed,  many 
which  have  never  been  detected  in  nature  have  been 
created  there. 

It  may  be  stated  that  urea  was  not  really  a  synthe- 
tic product,  because  it  was  only  converted  ammonium 
cyanate  which,  in  turn  was  not  obtained  synthetically, 
but  it  has  since  been  demonstrated  over  and  over 
that  this  compound  can  be  built  up  atom  l)y  atom 
from  its  elements.  'IMuis,  if  nitrogen  gas  is  passed 
over  charcoal  and  potassium  carbonate,  mixed  and 


ORGANIC    CHEMISTRY.  203 

heated  to  redness,  potassium  cyanid  is  formed;  and  if 
the  cyanid,  in  turn,  is  fused  with  lead  oxid,  it  takes  up 
the  oxygen,  becoming  converted  into  potassium 
cyanate.  Ammonia,  on  the  other  hand,  can  be 
formed  by  the  direct  union  of  nitrogen  and  hydrogen 
and  absorbed  by  water;  and  if  sulfuric  acid  be  added 
to  it,  it  is  neutralized  and  converted  into  ammonium 
sulfate.  If,  now,  the  potassium  cyanate  and  the 
ammonium  sulfate  be  dissolved  in  water,  the  solution 
evaporated  to  dryness  and  the  residue  exhausted 
with  alcohol,  upon  evaporation  the  alcohol  deposits 
urea,  the  following  decomposition  having  taken 
place: 

2KCNO  +  (NH4),S04  =  K,S04  +  2Cq(NH,)3 
potassium  +      ammonium      =     potassium   +       carbamid 

cyanate  sulfate  sulfate  (urea) 

Thus,  we  have  seen  urea  built  up  atom  by  atom 
from  the  elements;  whereas,  in  the  discovery  of 
Woehler,  it  was  a  simple  rearrangement  of  the  atoms 
in  the  molecule,  thus: 

NH.CNO  =  Cq(NH,), 
ammonium  =        urea 
cyanate 

THE  SCOPE  OF  ORGANIC  CHEMISTRY.— Until 

the  beginning  of  the  nineteenth  century,  chemistry 
was  concerned  mostly  with  the  products  of  the 
mineral  kindgom  or  with  those  of  the  animal  and 
vegetable  kingdoms.  Those  from  the  latter  two 
kingdoms,  which  Lavoisier  (1794)  showed  to  contain 
carbon,  hydrogen  and  oxygen,  were  called  "  organic  " 
and  those  which  were  obtained  from  the  mineral 
kingdom,  like  common  salt,  gyj^sum  or  water,  were 


204  PHARMAC'Eimc    CHEMISTRY. 

tailed  the  "inorganic."  Hut  among  those  of  the 
organic  compounds  which  contained  like  substances, 
many  possessed  different,  varying  properties.  Thus, 
sugar,  vinegar  and  alcohol  contain  the  same  elements 
— carbon,  hydrogen  ando.xygen — but  their  properties 
are  very  different  because  the  elements  exist  there  in 
very  variable  proportions.  Berzelius  (1814)  so  im- 
proved the  methods  of  organic  analysis  that  it  was 
possible  to  make  determinations  of  the  exact  composi- 
tion of  the  organic  acids  and  to  establish  the  atomic 
ratio  of  the  constituent  elements  one  to  another;  and, 
although  the  discovery  of  Woehler  was  well  known, 
as  was  the  discovery  of  acetic  acid  by  Melsens  (1842) 
and  Kolbe  (1844),  it  was  a  long  time  before  the  be- 
lief that  vital  activity  was  necessary  for  the  produc- 
tion of  organic  compounds,  disappeared.  There  is 
a  difference  between  an  organic  compound  and  an 
organism.  Compounds  can  be  created  artificially, 
organisms  cannot.  For  this  reason  it  is  safe  to 
believe  that  the  solution  of  the  problems  of  life's 
creation  is  as  yet  afar  off  and  the  breech  between  the 
laboratory  creation  and  that  of  the  organism  may 
never  be  mended.  At  least,  it  is  far  distant  at  the 
present  time. 

At  the  time  of  Woehler's  discovery,  organic 
chemistry  embraced  but  a  few  hundred  substances 
derived  from  the  animal  and  vegetable  sources. 
Now  it  contains,  as  has  previously  been  stated,  over 
one  hundred  thousand  artificial  products.  This 
most  extraordinarv  development  can  be  traced 
directly  to  two  ])rincipal  causes:  the  first  one  was 


ORGANIC   CHEMISTRV.  205 

the  formulation  of  the  laws  underlying  the  struc- 
ture of  organic  compounds  by  Kekule,  and  the 
second,  the  industrial  application  of  the  organic 
discoveries.  At  the  present  time  the  contributions 
of  organic  chemistry  to  mankind  are  many  and 
varied.  Thus,  foods,  medicines,  dyes,  soaps,  nitrogly- 
cerin and  dynamite,  paper  and  celluloid,  perfumes, 
ink,  artificial  silk,  are  all  organic  compounds,  and  at 
the  present  time  there  seems  no  apparent  limit  to  the 
development  of  the  industries  in  which  organic 
chemistry  plays  an  important  part. 

DISTINCTION  BETWEEN  ORGANIC  AND  INOR- 
GANIC CHEMISTRY.— The  necessities  for  this 
division  are,  primarily,  the  large  variety  and  com- 
plexity of  organic  compounds,  as  will  be  seen  by  the 
following  examples: 

Methane,  CH, 

Turpentine,         CjoH^g 
Cane-sugar  Cj.^H220n 

Morphin,  Q7H19NO3 

Hematin,  C32H32FeNjOg 

Starch  (soluble), C1200H2000O1000 

Secondarily,  owing  to  the  different  reagents  and  proc- 
esses necessary  for  the  production  of  the  variety  of 
compounds,  each  one  requires  a  treatment  of  its  own. 
Thus,  we  can  oxidize  iron  with  either  nitric  acid, 
chlorin  or  potassium  permanganate,  tlie  result  in 
each  case  being  the  same;  not  so  with  the  organic  sub- 
stances where,  by  the  employment  of  these  different 
oxidizing  agents,  a  different  product  would  be  ob- 


2o6  I'HARMACKUTIC    CHKMISTRV. 

taincd  in  each  case.  Lastly,  because  the  study  of 
organic  compounds  cannot  be  limited  to  the  knowl- 
edge of  their  components.  They  are  very  com])lcx 
in  structure.  One  who  has  studied  inorganic 
chemistry  wilf  recognize  at  sight  HNOg  to  be  nitric 
acid  and  HjSO^  to  be  sulfuric  acid;  but  to  see  a 
formula  like  CijHjoOu,  it  is  entirely  different.  Many 
organic  substances  have  the  same  composition  and 
molecular  formula,  but  ditYer  in  their  ])roperties. 
Such  substances  are  called  isomeric  {isos,  equal; 
meros,  part).  Isomerism  is  a  striking  characteristic 
of  many  organic  compounds;  thus,  the  formula 
CgHjjO^  represents  66  different  compounds.  To 
illustrate,  a  familiar  example  is  taken: 

Alcohol,  CjHgO,  is  a  liquid  having  a  boiling-point 
of  78°,  whereas  C2HgO  is  also  the  formula  of  methyl 
ether,  also  called-  dimethyl  ether,  a  liquid  having  a 
boiling-point  of  — 23.6°  C.  This  difference  in  the 
two  compounds,  having  the  same  composition  and 
molecular  formula  but  different  properties,  is  due  to 
the  arrangement  of  the  atoms  in  the  molecule.  Thus, 
the  carbon,  hydrogen  and  oxygen  are  ar-ranged  in  the 
alcohol  and  the  methyl  ether  as  follows: 

CH,  C  H, 

I  I 

CH2 O 

I  I 

OH  CH3 

alcohol  methyl  t  thcr 

Tlie  above  substamcs,  tlierofore,  are  isomeric,  or 
one.  is  an  isonier  of  tin-  olher. 


CHAPTER  XX. 

CARBON. 

The  principal  forms  of  carbon  are :  (</)  Crystalline — 
the  diamond,  the  purest  form  of  all;  the  graphite,  also 
called  plumbago  and  black  lead.  Graphite  is  used  in- 
lead  pencils,  crucibles,  stove  polish  and  as  a  conductc  r 
of  electricity  in  electrotyping.  {b)  Amorphous — the 
anthracite,  a  variety  of  coal  composed  of  almost  pure 
carbon  and  used  as  fuel;  the  charcoal,  of  which  two 
varieties  are  used — wood  and  animal  charcoal;  the 
latter  variety  obtained  b}-  incomplete  combustion  of 
bones.  Both  are  used  as  fuel,  absorbents  of  gases, 
decolorizers  and  disinfectants.  The  lampblack,  the 
lightest  form,  contains  some  hydrocarbons,  chiefly 
used  in  printer's  ink.  The  gas  carbon,  deposited  in 
retorts  in  coal-gas  manufacture,  is  hard  and  used  in 
arc-lights  and  in  galvanic  batteries. 

Combined,  it  is  found  in  the  form  of  carbonates 
and  bicarbonates  and  in  all  organic  substances, 
whether  of  vegetable  or  animal  origin.  Properties: 
All  varieties  of  carbon  are  insoluble  and  infusible,  but 
freely  combustible  (excepting  carbonates  and  bicar- 
bonates), burning  to  carbon  dioxid  in  air.  All  but 
the  diamond  are  good  conductors  of  electricity. 
There  are  two  oxids  of  carbon — CO,  carbonic  oxid, 
also  called  carbon  monoxid,  and  CO^,  carbon  dioxid, 
also  called  carbonic  acid.  Carbonic  oxid  is  pro- 
207 


2o8  I'llARMACEl'iK     (  HI.MISTKV. 

(liufd  1)\-  ihc  incomplete  C()ml)usli(jn  of  coal  in  the 
>lo\e,  or  it  can  be  made  artiticially  by  heating  oxalic 
acid,  in  \vhi(_h  case  CO  is  given  off  during  the  decom- 
position, or,  still,  by  the  interaction  of  sulfuric  acid 
and  oxalic  acid.     Reaction: 

QH^O,    +    H2SO,    =    CO    +    CO2    +    H,0. 
It  is  also  produced  in  the  manufacture  of  water-gas  at 
high  temperatures;  thus, 

C    +   H.O    =    CO    4-    H,; 
whereas,  at  lower  temperatures  CO,  forms.     Reac- 
tion: 

C    +    2H.,0    =    COo    -I-    2H.,. 
With    nickel,    CO    (carbonyl)    forms   a    compound 
known   as   nickel   tetracarbonyl,  Ni(CO)4.     Nickel 
tetracarbonyl   is    a    liquid    employed   in    dissolving 
nickel  out  of  low-yield  ores,  thus: 

Ni  -f  4  CO  =  Ni  (CO),, 

and  on  heating,  the  compound  is  resolved  as  follows 

Ni(CO),  =  Ni  +  4CO. 

Carbon   disnlfid,  thiocarbonic  anhydrid,  C/    ,  is 

a  clear,  colorless  liquid,  with  disagreeable  odor,  boil- 
ing at  47°  C,  sp.  gr.,  1.51 ;  it  forms  an  explosive  mix- 
ture with  air.  Gciod  solvent  for  sulfur,  iodin.  fats, 
resins  and  rubber. 

THE  NATURAL  SOURCE  OF  CARBON.— T he 
source  c)f  carl)on  com])ounds  in  nature  is  the  carbon 
dioxid  (CO..)  exhaled  by  animals  into  the  air.  it 
is  absorbed  by  the  leaves  of  plants  and  there,  in  the 
presence  of  moisture  and  by  the  agency  of  the  sun's 
rays  is  converted  by  the  chlorophyl  (leaf-green)  into 


ORGANIC   ELEMENTS.  209 

Starch  or  similar  substance.  Thus,  xCOj  molecules 
+  vH.^O  molecules  =  z  molecules  of  CgHioOs,  or 
starch. 

With  the  nitrogen  of  the  air  it  forms  in  the  plant 
bodies  substances  like  the  proteins,  of  which  albumin 
is  an  example.  These  substances  when  ingested  into 
the  human  body  are  decomposed  into  water  (HjO), 
carbon  dioxid  (COj),  and  urea  (CO(NH,),). 

From  the  above  it  will  be  seen  that  the  changes  in 
the  plant  bodies  are  synthetic,  while  the  changes  in 
the  human  body  are  analytic.  In  the  plants,  energy 
s  formed  and  stored;  in  the  human  body,  it  is  evolved 
or  expended. 

Elements  Entering  Organic  Compounds. — Carbon 
compounds  contain  few  elements,  but  many  atoms. 
They  always  contain  carbon,  usually  hydrogen, 
often  oxygen  and  nitrogen,  and  sometimes  sulfur 
and  phosphorus.  They  are  very  complex  in  struc- 
ture. Thus,  hemoglobin,  the  red  coloring  matter  of 
the  blood,  contains  in  its  molecule  600  atoms  of  car- 
bon, 960  atoms  of  hydrogen,  154  of  nitrogen,  179 
oxygen  and,  in  addition,  3  atoms  of  sulfur  and  i  of 
iron.  Whereas,  in  inorganic  chemistry,  we  deal 
with  about  85  elements,  each  capable  of  forming  but 
a  few  compounds,  carbon,  on  the  other  hand,  is 
capable  of  forming  such  great  multitude  of.  com- 
pounds with  so  few  elements,  it  becomes  a  matter  of 
great  curiosity  how  this  can  occur.  The  reason  for 
it  is,  besides  the  already-mentioned  isomerism,  a 
very  interesting  fact,  namely,  that  carbon  can  unite 
with  itself  into  chains  or  rings  to  a  very  remarkable 
14 


2IO  I'llARMACEUTlC    CHEMISTRY. 

degree,  and  around  these  chains  or  rings  other  atoms 
are  attached.  A  chain  is  a  series  of  multivalent  atoms 
so  combined  that  free  bonds  are  left  unsaturated. 
Thus,  carbon  can  unite  in  three  ways:  linked  by  one 
bond  and  leaving  six  unsaturated  bonds,  in  which 
case  the  linking  is  known  as  paraflBnic;  linked  by  two 
bonds,  leaving  four  unsaturated  bonds,  in  this  case 
the  linking  being  known  as  olefinic;  and,  lastly, 
linked  by  three  bonds,  leaving  two  unsaturated 
bonds,  in  which  case  the  linking  is  known  as 
acetylenic. 

c=  c=  c— 

I  II  III 

c=  c=  c— 


paraffinic  bond  olefinic  bond  acetylenic  bond. 

All  the  above  Unkings  are  called  open  chains. 
Besides  these,  the  carbon  links  its  atoms  by  alternate 
double  and  single  bonds,  in  which  case  it  is  km-wn  as 
closed  chain  or  ring  linkage,  as  in  the  case  of  ben- 
zene, in  which  closed  chain  of  C\  forms  a  hydrocarbon 
having  the  formula  C|;H„. 

H 

I 
C 

/\ 
H— C      C— H 

-        •       II        I 
H— C      C— H 

C 


H 


ORGANIC    COMl'OUNDS.  2  I  1 

We  have  seen  similar  linkings  in  inorganic  chemis- 
try, as  in  the  case  of  oxygen  (O   =  O),  and  in  the 

O 
case  of   ozone  X\.      The  quantivalence  oj  carbon 
is  always  4.     O — O 

THE  CLASSIFICATION  OF  ORGANIC  COMPOUNDS. 

The  immense  number  of  substances  comprising 
the  study  of  organic  chemistry  renders  classification 
difficult.  It  is  primarily  divided  into  two  grand 
classes  or  divisions:  (i)  the  methane,  paraffin, 
fatty  or  marsh-gas  series;  (2)  the  benzene,  ring  or 
aromatic  series.  In  the  first  class  all  the  organic 
substances  are  considered  as  derivatives  of  methane 
(CH^),  and  in  the  second  class  they  are  con- 
sidered as  derivatives  of  benzene  (CeH^).  Each  of 
these  two  hydrocarbons  forms  a  variety  of  deriva- 
tives which  may,  for  convenience,  be  divided  into 
classes  : 

(i)  Hydrocarbons — compounds  containing  carbon 
and  hydrogen  only,  as  methane  (CH^),  benzene 
(CgHg),  naphthalene  (CjoHg). 

(2)  Alcohols — hydrocarbon  radicals  combined  with 
a  hydroxyl  group,  as  ethyl  alcohol  (CjH^OH). 

(3)  Aldehyds — compounds  of  hydrocarbon  radi 
cals  with  — CHO  group,  as  acetaldehyd  (CH3CHO). 
They  are  also  defined  as  the  oxidation  products  of 
primary  alcohols. .    (Alcohols  less  2H.  atoms.) 

(4)  Ketones — compounds  of  the  divalent  radical, 
carbonyl,  =  CO,  united  with  two  monovalent  alkvl 


212  PHARMACEUTIC    CHEMISTRY. 

radicals,  as  CH3 — CO — CH3,  dimethyl  ketone,  or 
acetone.  (Also  defined  as  oxidation  products  of 
secondary  alcohols.) 

(5)  Acids — compounds  of  hydrocarbon  radicals 
united  to  a  carboxyl  group  ( — COOH),  as  acetic 
acid,  CH3COOH. 

(6)  Ethers — compounds  of  hydrocarbon  radicals 
with  oxygen;  also  defined  as  alkyl  oxids.  Example, 
common  ether,  also  called  diethyl  ether,  CgH^ — O — 
C2H5. 

(7)  Esters — alkyl  salts.  They  are  also  defined 
as  acids  in  which  the  hydrogen  of  the  carboxyl  is 
replaced  by  an  alkyl.  Example,  acetic  ether, 
CH3COOC2H5. 

(8)  Carbohydrates — compounds  of  carbon,  with 
hydrogen  and  oxygen  in  the  proportion  to  form 
water,  as  glucose,  CgHjjOg. 

(9)  Amins  and  Anids:  Amins  are  ammonias  in 
which  one,  two  or  all  three  hydrogens  have  been 
replaced  by  alkyl  groups,  as  methylamin,  NH2CH3, 
dimethylamin,  NH  (0113)2,  or  trimethylamin, 
N(CH3)3.  Amids  are  acids  in  which  the  OH  group 
of  the  carboxyl  has  been  replaced  by  the  amido 
(NH,)  group,  as  acetamid,  CH3CONH2. 

(10)  Cyinids — compounds  and  derivatives  of 
cyanogen,  C2N2. 

(11)  Proteins — compounds  of  complex  structure, 
containing  carbon,  oxygen,  hydrogen,  nitrogen  and 
sulfur  and  often  ])hosphorus  and  .iron,  as  albumin, 
C72HU2N18SO22,  or  hemoglobin,  C6ooH98oN,54079S3Fc. 

(12)  Acid  halids  are  organic  acids  in  which  the 


ORGANIC    COMPOUNDS.  213 

hydroxyl  has  been  replaced  by  a  halogen,  as  acetyl 
chlorid^  CH3CO.CI. 

(13)  Anhydrids — acids  deprived  of  water,  as 
acetic  anhydrid,  (CH3CO)20. 

(14)  Or gano-metaUk compounds — alkyl compounds 
of  the  metals,  as  zinc  ethyl,  Zn(C2H5)2. 

(15)  Alkyl  halids — compounds  of  alkyl  with 
halogens,  as  methyliodid,  CH3I;  ethyl  bromid, 
CjHgBr;  propylchlorid,  C3H7CI. 

Another  method  of  classification  is  that  based  on 
the  composition  and  properties  of  many  of  the 
members  of  the  different  families  of  organic  com- 
pounds. For  instance,  in  the  class  of  hydrocarbons, 
each  member  behaves  toward  reagents  in  a  manner 
much  like  every  other  member  of  the  same  class,  and 
the  same  may  be  said  of  the  class  of  alcohols,  alde- 
hyds  and  ethers;  but  although  the  chemical  behavior 
of  each  family  is  the  same,  the  physical  properties, 
such  as  specific  weight,  melting-points  and  boiling- 
points  of  the  individual  members,  vary  with  each 
member.  Thus,  increased  molecular  weight  usually 
shows  a  higher  boiling-point;  the  first  jour  members 
of  the  paraffin  series  are  gases,  the  next  eight  are 
liquids,  while  those  having  the  largest  carbon  molecule 
are  solids. 


CHAPTER  XXI. 

HOMOLOGY. 

Upon  examination  of  the  first  tive  members  of  the 
methane  series,  we  find  that  there  is  a  simple  ratio 
of  difference  between  each  of  the  individual  mem- 
bers. It  will  be  observed  that  the  ratio  of  differ- 
ence between  the  members  is  CHj.  It  is  apparent 
that  the  successive  members  can  differ  only  by  the 
same  group,  inasmuch  as  the  carbon  has  but  four 
valences,  of  which  two  have  been  satisfied  Ijy  the 
hydrogen  and  two  remain  unsaturated.  This  rela- 
tion is  characteristic  not  only  of  the  paraffin  series, 
but  also  of  the  other  hydrocarbon  families.  This 
relationship  is  termed  homology,  and  the  individual 
members  arc  called  homologous. 

ALIPHATIC  SERIES. 

The  Hydrocarbons. 

The  hydrocarbons  have  been  defined  as  com- 
pounds of  carljon  and  hydrogen  only,  and  hence 
their  name.  They  occur  in  nature  in  very  large 
quantities  and  are  the  starting-point  of  a  whole 
series  of  aliphatic  or  open-chain  compounds. 

Occurrence. — The  hydrocarbons  found  in  nature 
arc  almost  c.xchisivcly  vcgijtablc,  very  few  being 
animal   jji-oducls,  nnd   they  are  generally   sui)i)osed 

2V..\ 


HYDROCARBONS.  215 

to  be  products  of  decc^mposition.  Several  theories 
have  been  advanced  to  explain  their  formation  in 
nature: 

First,  the  chemical  theory.  Based  on  the  fact 
that  when  carbids  are  treated  with  water,  hydrocar- 
bons form;  thus: 

AI4C,,  +  i2H,0  =  3CH4  +  4Al(OH)3  ^ 
aluminum     +        water        =     methane     +  aluminum 

carbid  hydroxid. 

Second,  the  vegetable  theory,  also  called  the 
theory  oj  petroleum  formation.  This  depends  upon 
the  fact  that  when  organisms  act  upon  woody  fiber 
(cellulose),  in  presence  of  moisture,  as  in  the  case  of 
the  decay  in  the  stagnant  pools  of  marshes,  hydro- 
carbons are  formed.     Thus: 

(C6HioO,)n       +      (H^)n      =  (3CQ.)n         -f    (3CH.)n 

cellulose  -|-       water        =    carbon  dioxid  -\-    methane 

Third,  the  biologic  theory.  This  theory  purports 
that  animal  remains,  under  pressure  and  with  suf- 
ficient water,  bring  about  a  reaction  resulting  in 
the  formation  of  hydrocarbons.  It  is  difficult  at 
this  stage  and  time  to  say  definitely  which  of  these 
three  theories  is  the  most  probable.  All  three  may 
be  correct:  paraffins  may  originate  from  either 
animal,  vegetable  or  chemic  matter,  or  all  three 
combined. 

The  hydrocarbons  are  very  important  in  the 
sense  that  they  are  looked  upon  as  the  fundamental 


2l6  PHAKMACEirXIC    CHEMISTRY. 

compounds  of  organic  chemistry  from  which, 
directly  or  indirectly,  all  the  other  organic  com- 
pounds are  derived.  They  are  also  important,  per- 
haps, for  the  reason  that  comparatively  few  of  the 
carbon  compounds  do  not  contain  hydrogen  and  it  is, 
therefore,  practical  to  consider  all  organic  compounds 
as  either  substitution  or  addition  products  of  the 
hydrocarbons.  All  the  hydrocarbons,  as  has  been 
stated  before,  are  divided  into  series,  each  having  a 
definite  general  formula  which  applies  to  any  indi- 
vidual member  of  the  entire  series.  Thus,  the  most 
usual  classification  of  hydrocarbons  is  into  the  four 
general  classes  or  series:  (i)  The  methane,  paraffin 
or  chain  series;  (2)  the  ethylene  or  olefin  series; 
(3)  acetylene  series;  (4)  the  benzene,  aromatic  or 
ring  series. 

The  general  formula  of  the  first,  or  methane  series, 
is  CnHjn+a-  The  general  formula  of  the  olefine 
series  is  CnHj^.  The  general  formula  of  the  third, 
or  acetylene  series,  is  Cj,H2n_2-  The  fourth,  or  ben- 
zene series,  has  the  general  formula  of  CnH2n_,;- 

FAMILIAR  EXAMPLES  OF  THE  HYDROCARBONS 
AND  THEIR  GENERAL  PROPERTIES. 

All  students  are  acquainted  with  ordinary  turpen- 
tine, also  most  of  you  have  seen  the  oils  of  lemon 
peel  or  orange  peel.  Now  you  will  recall  that  while 
the  turpentine  oil  is  a  colorless,  water-white  liquid, 
the  lemon  oil  is  a  straw-colored  liquid,  and  the  oil  of 
orange    peel,    a    still    darker   ycUow-colorcd    liquid. 


PARAFFINS.  217 

One  will  also  recall  that  the  odor  of  turpentine  is 
very  unlike  that  of  lemon  and  less  like  that  of  the 
orange-peel  oil;  and  ycl,  <///  the  three  substances  are 
hydrocarbons  belonging  to  the  same  series  and  having 
tlie  same  chemical  Jormnla,  CjoHjg.  The  above  il- 
lustration is  one  of  the  striking  examples  of  isomerism, 
each  of  the  substances  being  an  isomer  of  the  other. 
The  next  familiar  example  of  the  hydrocarbons  is 
methane,  CH^,  which  is  the  principal  constituent  of 
our  illuminating  gas.  The  ordinary  benzin,  which 
we  use  for  cleaning  purposes  and  as  a  fuel,  is  chemi- 
cally a  mixture  of  two  hydrocarbons— hexane,  CgHj^, 
and  heptane,  CyHjg.  The  ordinary  petroleum  jelly, 
better  known  as  petrolatum  or  vaselin,  is  nothing 
more  nor  less  than  a  mixture  of  five  hydrocarbons, 
from  CigHg^  to  CjqH^j- 

Properties. — ^The  hydrocarbons  are  insoluble  in 
water,  but  soluble  in  alcohol,  ether,  carbon  disulfid, 
benzol,  etc.  They  are  generally  colorless,  frequentlv 
possessing  peculiar  odor.  They  exist  in  all  three 
states  of  aggregation;  thus,  the  first  jour  of  the  paraf- 
fins are  gases;  the  next  seven  are  liquids  and  those  con- 
taining over  twelve  atoms  of  carbon  in  a  molecule  are 
solids. 

SYNTHESIS  OF  THE  MEMBERS  OF  THE 
PARAFFIN  SERIES. 

There  are  four  methods  of  synthesis  emploved: 

(i)  By  treating  alkyl  halids  with  nascent  hydrogen. 

An  alkyl  halid  is  a  compound  in  which  one  or  more 


2l8  PHARMACEUTIC    CHEMISTRY. 

hydrogen  atoms  of  the  paralTin  liavc  been  r(.'])hicc(l  l)y 
a  halogen,  thus: 

(a)    CU^  +        ^2        =     CH,      +         HI 

methyl  +  hydrogen  =  methane  +         acid 
iodid  tiydriodic 

{b)  C\H^Br+         H,  C^He   +        HBr 

et'"'yl    +  hydrogen  =  ethane  +         acid 
bromid  hydrobromic 

By  treating  any  alkyl  hahd  (iodid  or  bromid)  with 
HI,  the  corresponding  paraffin  is  formed.  The 
organo-metallic  compounds,  Hke  zinc  ethyl,  when 
treated  with  water,  also  yield  paraffins.  This  latter 
method,  however,  is  a  dangerous  one  for  the  begin- 
ner, in  that  the  zinc  alkyls  are  very  inflammable, 
even  in  contact  with  air: 

CHs— Zn— C^H,  +  2H,0  =  2C,H6  +      Zn(OH), 
zinc  ethyl  +  water  =  ethane  -f  zinc  hydroxid 

(2)  By  treating  an  ethereal  salt  icitli  alkali  hydroxids 
or  sod  a -I  i  Die: 

NaOH4-(\-iO 
CH,— COONa  +        NaDH        =       CH,      +  Na^CO; 
sodium  acetate  +      soda-lime      =  methane  +   sodium 

carbonate 

(3)  By  uniting  the  elements: 

(<;)     (j)  C       +     O    =  CO 

(2)  CO    +  3H,   =  CH,     -f  H.,0 
methane 


(&)  CS,  +  2H  S  +  8Cu  =  CH,  +  4Cu,S 
carbon  +  hvdrogen-|-  copper  =^ methane  +  cujirous 
disulfid  sulfid  sulfid 


PARAFFINS.  219 

There  is  also  an  electrolytic  method  of  synthctizing 
paraffins. 

Obtaining  Higher  Paraffins. — By  treating  the 
alkyl  halids  with  metallic  sodium,  higher  paraffins 
of  the  series  may  be  obtained: 

(a)    CH3I    +     Na.      +    ICH.       =    C.He    +   2NaI 

ethane 

{b)    C.H5I    +     Na.     +      JCH,       =    C3H8    +   2NaI 
propane 

(c)  C.HsI    +     Na.      +     ICH;     =   C4H10  +  2NaI 

butane 

(d)  C3H7I    +    Na^     +     ICH,     =_C5Hi,  +  2NaT,elc. 

pentane 

COMPOSITION   OF  METHANE. 

Methane  has  the  composition  CH^.  It  is  a  gas 
having  the  molecular  weight  of  16,  and  it  is  most 
commonly  known  as  "marsh  gas,"  because  when  a 
rod  is  pushed  into  a  stagnant  pool  on  the  marshes  a 
gas  bubbles  Out,  which  ignites.  From  this  fact  of 
the  discovery  of  methane  upon  the  marshes,  the 
term  "marsh-gas  series"  has  been  applied  to  the 
paraffins.  The  gas  is  also  commonly  found  in  the 
coal  mines  where  it  is  known  as  fire-damp,  and 
where  it  has  caused  many  and  very  disastrous  ex- 
plosions owing  to  its  inflammability.  The  origin  of 
both  marsh-gas  and  fire-damp  is  without  a  doubt 
similar,  and  dependent  upon  the  action  of  micro- 
organisms on  cellulose.     This  fact  has  been  demon- 


220  PHARMACEUTIC    ClIKMISTRY. 

strated  even  in  the  laboratory  where  filter  paper, 
whicli  chemically  is  cellulose,  under  the  influence  of 
(lie  microorganisms  most  common  to  sewage,  was 
converted  into  a  decomposition  product  and  gave 
rise  to  the  formation  of  methane.  Methane  has 
also  been  found  in  the  crevices  of  rocks  covered 
with  limestone  or  shale,  where  it  exists  under  a  high 
pressure.  When  such  a  rock  is  bored,  great  quanti- 
ties of  gas  will  escape,  which  in  Pennsylvania, 
Indiana  and  other  States  has  proved  a  very  economic 
source  of  fuel  under  the  name  of  natural  gas. 

Specific  Properties.— The  characteristic  properties 
i)f  methane  apply  to  every  member  of  the  series; 
thus,  all  the  paraffins  are  very  stable;  they  all  resist 
the  action  of  reagents  markedly,  with  the  exception 
of  chlorin  gas.  Their  boiling-points  rise  30  degrees 
for  every  CHj  group  added,  and  their  molecular 
weights  increase  by  14  criths  for  every  CH,  group. 
They  are  all  saturated  compounds  and  cannot 
directly  unite  with  elements  or  residues,  but  indi- 
rectly form  compounds  after  the  removal  of  part  or  all 
of  their  hydrogen.  Such  compounds  are  known  as 
substitution  products.  These  substitution  products 
are  very  numerous.  From  the  al)ove  discussion  it 
will  be  seen  that  a  thorough  study  of  the  derivatives 
of  one  hydrocarbon  will  apply  to  the  derivatives  of  all 
the  other  hydrocarbons. 

The  appended  tat)le  of  hydrocarbons  of  the  paraf- 
fin series  should  be  studied  very  carefully  by  the 
student,  and  their  formulas,  molecular  weights, 
boiling  or  melting-points  noticed. 


PARAFFINS.  2  2 

TABLE  OF  THE  PARAFFINS. 


(.icneral  Formul 


-CnH, 


Name. 


J;  re 


Methane 

Ethane 

Propane 

Butane  \ 

Methyl  propane  / 

Pentane 

Methyl  butane         1 
Dimethyl  projiane  J 

Hexane  

Dimethylisopropylmethane  j 
Dimethylpropylmethane  [ 
Methyldiethylmethane  f 

Trimethylcthylmethane        J 

Heptane 

Isoheptane  ] 

Ethylpentanc         }■   

Dimethylpentane  j 

Octane 

Nonane 

Decane  

Undecane 

Dodecane 

Eicosane  

Hentriacontane 

Pentatriacontane 


C2H6 
C3H8 
C4H10 


C6H,4 


C,Hi 


CsH.s 

CgH.o 
CloH,2 

C„H,4 

C.oH,, 
C31H64 

C35H,.l 


-186 


36 

31 

9 

69 

58 

62 

64 

48 
98.4 

90   ' 

95 

87 
125 
150 
173 
195 
214 
205 
302 
331   I 


io.  60  -  0°  C 


0-633  - 
0.627  - 

0.6654- 
n.668  - 
I0.676  - 
0.676  - 
0.648  - 
0.688  - 
0.697  - 


0.711 

0.718 

0-733 

0-745 

0.774 

0-773 

37  0-778 

68  0.781 

75,0.782 


-15°  C. 
-15°  C. 

-15°  C. 
-17°  C. 

-  o°C. 
-20°  C. 
-20°  C. 
-15°  c. 

-  o°C. 
-27°  C. 

-  o°C. 

-  o°C. 

-  o°C. 

-  o°C. 

-  o°C. 


THE  PETROLEUM  INDUSTRY. 

All  of  these  hydrocarbons  are  found  present  in 
petroleum,  of  which  some  of  the  lower  members  have 
been  isolated,  but  the  higher  paraffins  are  very 
difficult  to  isolate.  The  paraffins  are  likewise  found 
associated  in  smaller  quantities  in  natural  gas,  in 
asphaltum  and  in  earth-wax  (ozokerite). 


2  22  PHARMACEUTIC    CHEMISTRY. 

Petroleum  was  discovered  in  Pennsylvania  by 
Colonel  Drake  in  i860,  and  from  that  time  the 
petroleum  industry  dates.  Since  that  time  oil  has 
been  found  in  Indiana,  Ohio,  Colorado,  California, 
Texas,  Canada  and  other  places,  from  which  the  oil 
is  distributed  by  means  of  so-called  "pipe  lines"  to 
distances  of  more  than  three  hundred  miles.  The 
reservoirs  holding  the  crude  oil  and  covered  by  im- 
pervious lime  or  shale  rock,  when  punctured,  emit 
petroleum  to  the  surface  by  hydrostatic  pressure  of 
the  water  found  within  the  crevices,  which  forces  the 
oil  out  in  enormous  quantities.  Crude  petroleum 
Hows  from  one  to  fifty  thousand  barrels  from  one 
well  per  day.  The  crude  oil  is  not  always  uniform 
in  composition;  thus,  in  the  Russian  petroleum  oil 
found  in  the  neighborhood  of  the  Caspian  Sea,  and 
in  that  found  in  Polish  Galicia,  naphthalenes  are 
found.  Crude  oil  is  subjected  to  fractional  distilla- 
tion in  large  iron  stills  and  purified  by  treatment 
with  chemicals.  The  Russian  oil  contains  less  of 
the  lower  boiling  fractions  than  the  American  oil, 
and  its  composition  may  be  stated  to  be  as  follows: 
illuminating  oil,  30%;  lubricating  oil,  20%;  and 
solar  oil  (a  heavy  oil  used  for  fuel),  35%;  coke  and 
inorganic  substances,  15%.  The  American  oil,  on 
the  other  hand,  consists  of  over  50%  of  the  lighter 
fractions  and  considerably  smaller  proportions  of 
lubricating  oil  and  paratTms.  When  subjected  to 
fractional  distillalion  it  is  first  separated  into  three 
main  fractions: 

'JMie  first  fraction  up  to  150°  C.  constitutes  crude 


PARAFFINS.  223 

bcnzin;  the  second  fraction  up  to  300°  C.  consti- 
tutes kerosene;  and  the  third  fraction  above  300°  C. 
constitutes  the  paraffin  oil,  paraffin  wax  and  coke. 
The  first  two  fractions  are  further  separated  by  the 
"crack"  method  of  distilling  Hghter  oils.  This 
method,  however,  should  be  avoided  when  the 
heavier  fractions  are  desired.  The  different  frac- 
tions may  be  designated  and  identified  as  follows: 

Name.  Fraction.        Constituejits. 

Boiling-point. 

Cymogene, 0°  C. 

Rhigolene, i8°C. 

Petroleum  ether, 40-    70^  C.     C5H12  -f  C6H14 

Petroleum  naphtha  or  ligroin,    8o-i2o°C.     C6H14  —  CsHis 
Petroleum  benzin  or  benzoline,  120  — 150°  C.     CsHjs  —  C9H20 
Kerosene,    photogene,    head- 
light oil, 150  — 300°  C.    C10H22-C16H34 

Lubricating  oil  (also  called  paraffin  oil) — Sp.  gr.  0.87  to  0.94. 

Petrolatum, Melting-point  varies  from  45  to  48°  C. 

Paraffin   wax, Melting-point  varies  from  52°  to  80°  C. 

Coke, 

NOMENCLATURE  OF  THE  HYDROCARBONS. 

The  hydrocarbons  of  the  paraffin  series  are  al- 
ways denoted  by  the  termination  "anc."  The 
first  four  members  of  the  series,  methane,  ethane, 
propane  and  butane,  have  special  names.  The 
remaining  members  of  the  group  are  usually  denoted 
by  the  Greek  or  Latin  numeral  corresponding  to  the 
number  of  carbon  atoms  in  the  molecule.  Thus, 
C5H12  is  called  pentane;  CgHig  is  called  octane; 
Ci2^26  i^  called  dodecane;  and  CgjH,.^,  hentriacon- 
tane,  etc.  It  is,  however,  necessary  to  consider 
other  groups  of  atoms  which  do  not  exist  in  the  free 
state,  but  which  are  derived  from  the  above  hvdro- 


224  PHARMACEUTIC    CHKMISTRV. 

carbons  by  the  removal  of  a  hydrogen  atom.  These, 
it  will  be  seen,  are  not  saturated;  they  have  the 
general  formula  C^H^n  +  i,  and  are  usually  denoted 
as  "  unsaturated  hydrocarbons,"  hydrocarbon  radi- 
cals or,  more  commonly,  alkyl  radicals  or  groups. 
Individually,  they  are  denoted  by  changing  the 
termination  of  the  corresponding  hydrocarbon  from 
"ane"  to  "yl."  In  this  way,  from  methane  (CHj 
we  obtain  methyl  (CH,);  from  ethane  (CjHg)  we 
obtain  ethyl  (CjHg);  from  propane  (CgHg),  propyl 
(C3H7);  from  dodecane  (CijHje),  dodecyl  {C^-yJi^f,)- 
The  general  name  saturated  hydrocarbons  (because 
they  are  saturated  with  hydrogen),  is  frequently 
interchangeable  with  paraffins,  because  one  of  the 
substances  obtained  from  this  series,  and  which  is 
a  mixture  of  the  higher  members,  is  paraffin  wax. 
The  word  paraffin  is  derived  from  two  Greek  words 
— "parum"  little,  and  "a^m^"  affinity^indicative 
of  their  resistance  to  the  action  of  the  chemical 
reagents.  Petroleum,  for  instance,  which  may  l)c 
taken  as  a  type  of  the  hydrocarbons,  is  not  affected 
by  either  HCl,  HjSO,,  Brj  nor  Ij,  but  freely  I)y  CL 

ADDITION  AND  SUBSTITUTION. 

Chlorin,  as  is  well  known,  combines  directly  with 
the  paraffins,  and  the  action  is  best  promoted  i)y 
sunlight.  Thus,  we  find  upon  examination  of  such 
a  reacti(m,  two  different  compounds  resulting,  which 
mav  be  illustrated  bv  the  following  reaction: 
CH,  4-  CU  =  CH.Cl  +  HCl. 
One   of    tiic   i)r()<lu(ts   is   monuchlurniclhanc,   com- 


PARAFFINS.  225 

nionly  called  methyl  chlorid,  the  other  is  hydro- 
chloric acid.  If,  however,  we  allow  chlorin  to  act 
on  carbon  monoxid  (carbonyl),  as  in  the  formation 
of  carbonyl  chlorid  (phosgene),  a  different  reaction 
takes  place.  To  illustrate,  CO  +  CI,  =  COClj. 
The  compound  having  the  formula  COClj  is  the  only 
product  of  the  reaction.  In  the  first  reaction  we 
have  removed  one  of  the  hydrogens  of  the  compound 
CH4,  and  replaced  it  with  a  chlorin  atom.  In  the 
second  reaction  we  have  added  all  of  the  chlorin 
directly  to  the  carbonyl,  replacing  nothing  and 
forming  no  by-product.  The  formation,  therefore, 
of  methyl  chlorid  illustrates  substitution,  while  the 
formation  of  carbonyl  chlorid  illustrates  addition. 
Among  the  aromatic  products  we  find  many  practical 
illustrations  of  addition  and  substitution.  To  il- 
lustrate, starting  with  benzene,  CgHg,  we  obtain 
several  benzene  chlorids,  as  benzene  dichlorid, 
CgHgCl,;  benzene  tetrachlorid,  CgHgCl^,  and  ben- 
zene hexachlorid,  CgHgClg.  These,  it  will  be  seen, 
are  addition  (additive)  products.  On  the  other 
hand,  such  derivatives  of  benzene  as  monochlor- 
benzene,  CgHgCl;  dichlorbenzene,  CgH^Clj;  penta- 
chlorbenzene,  CgHClj,  and  hexachlorbenzene,  CgClg, 
are  known  as  substitution  (substitutive)  products. 
It  is  necessary  that  the  student  be  able  to  clearly 
distinguish  between  these  two  classes  of  derivatives. 
The  nomenclature  of  these  classes,  illustrated  above, 
may  further  be  exemplified  by  the  following  paral- 
lel from  inorganic  chemistry:  benzene  dichlorid 
(CgHgCl,),  which  is  an  addition  product,  may  be 
15 


226  PHARMACEUTIC    CHEMISTRY. 

compared  to  carbon  disulfid  (CS2);  whereas  the  sub- 
stitution products  may  be  distinguished  by  attaching 
the  name  and  numerical  value  of  the  substitutive 
element  or  group  to  the  fundamental  name.  For 
example,  to  the  compound  CgH^Cl,,  in  which  it  will 
be  seen  that  two  chlorin  atoms  M'ere  substituted  for 
tivo  hydrogen  atoms  of  the  benzene,  the  name  di- 
chlorbenzene  is  given.  Another  way  of  distinguish- 
ing between  these  two  is  by  mentioning  the  funda- 
mental name  first  and  the  additive  group  last  in  the 
addition  products,  and  the  substitutive  group  first 
and  the  fundamental  name  last  in  the  case  of  sub- 
stitution products. 

Further  illustration  may  be  drawn  from  the  action 
of  chlorin  upon  marsh  gas.  We  have  seen  at  the 
beginning  of  this  chapter  that  when  marsh  gas  has 
been  acted  upon  by  chlorin,  methyl  chlorid  and 
hydrochloric  acid  were  formed.  By  further  action 
of  chlorin  on  the  so  produced  chlorids,  the  entire 
hydrogen  in  the  molecule  of  methane  may  be  sub- 
stituted or  replaced  bv  the  chlorin;  thus: 

CH3CI    4-    CU    =    C-//X7,    +    HCl 
Dichlormethane,  also  called  methylene  chlorid: 

CH.,CU    +    CI,    =    CHCl^    +    HCl 
Trichlormethane,   also   called    methenyl   chlorid   or 
chloroform: 

CHCl,    +    CU    =    Ca^    +    HCl 
Tetrachlormethane,  also  called  carbon  tetrachlorid. 

Of  these  the  tri-  and  tetra-\\i\\o\A  derivatives  arc 
the  only  ones  of  practical  im])ortance  owing  to  their 
use  in  the  arts  and  in  medicine. 


PARAFFINS.  227 

HOMOLOGUES  OF  METHANE. 

METHANE  is  the  simplest  of  all  carbon  compounds 
in  that  it  contains   the  lowest   number   of   carbon 
and  hydrogen  atoms.     Its  formula  (CH J  structural 
H 

formula,  H — C — H,  shows    it    to  contain    but   one 

I 
H 

carbon  atom.  It  can  be  synthetized  in  the  labora- 
tory by  heating  together  sodium  acetate  and  lime: 

2CH3COONa  +  Ca  (OH)^  =  2CH,  +  Na^COj 
+  CaCOg. 

Another  method  consists  of  passing  a  mixture  of 
hydrogen  sulfid  and  the  vapor  of  carbon  disulfid 
over  red-hot  copper: 

2H2S  +  CS2  +  8Cu  =  CH,  +  4  Cu^S. 
A  third  method  of  producing  marsh  gas  is  by  the 
action  of  water  on  aluminum  .carbid,  according  to 
the  following  reaction: 

A1,C3  +  i2H,0  =  3CH,  +  4AI  (OH)3. 
Lastly,  it  may  be  separated  from  coal  gas,  of  which  it 
constitutes  34%. 

Description. — Methane  is  a  colorless,  tasteless  gas 
which  may  be  condensed  to  a  liquid  by  high  pressure 
at  very  low  temperatures.  Chemically,  methane  is 
very  stable,  it  kindles  at  a  higher  temperature  than 
either  hydrogen  or  amorphous  carbon  which  accounts 
for  the  efficiency  of  the  Davy  safety  lamp.  With 
chlorin,  methane  forms  a  violently  explosive  mixture. 


22«  PHARMACEUTIC    CHEMISTRY. 

t'S|)t'(iall}-  in  direct  sunlight.  This  action  is  niodi- 
f'led  somewhat  in  ditTused  dayhght. 

ETHANE  (C.Hj,  the  second  member  of  the 
paraffin  series,  may  I)e  prepared  by  treating  alkyl 
halid  with  metallic  sodium  or  zinc  (alkyl  halids  are 
compounds  of  a  hydrocarbon  radical  with  a  halogen), 
or  it  may  be  prepared  by  warming  ethyl  iodid  with 
zinc-copper  couple  and  water: 

(i)  2CH3T    +   Na,   =   CH3— CH3   +    2XaI. 

(2)  C,H,I  +  H2  =  CjHg  +  HI. 

There  is  also  an  electrolytic  method  for  the  pro- 
duction of  ethane.  From  the  method  of  its  prep- 
aration we  may  regard  ethane  as  composed  of  two 
methyl  groups  united  together 

H 


H— C— H 


CH3 

I 


or  more 
TT p TT        compactly,      CH3, 

I  '  Ethane. 

H 

(CjHg);  or  we  may  regard  it  as  composed  of  the 
alkyl  ethyl,  and  hydrogen,  CoHg — H.  =  ethyl  hydrid. 

Properties. — Ethane  is  a  gas  condensable  to  a 
liquid  more  readily  than  methane.  Liquid  ethane 
has  a  boiling-point  of  — 90°  C.  Ethane  burns  witli 
a  luminous  llame  and  in  every  other  respect  closely 
resembles  methane.  Examination  of  its  methods 
of  preparation  uniformly  show  that  the  ethyl  group 
must  contain  one  methyl  group. 

PROPANE   ((".(Hj.      I'ropane  is  a  gas  which  can 


PARAFFINS.  229 

he  prepared  by  treating  a  mixture  of  methyl  and 
ethyl  iodids  with  metallic  sodium: 

QH,!    +    CH3I    +    Na^    =    C3H8    +    2NaI. 
It  may  also  be  prepared  from  zinc  propyl  or  from 
])ropyl  iodid.     Its  graphic  formula  is 
H 

H— C— H  CH, 

I  I 

H— C— H         < •     CH2 

I  I 

H— C— H  CH3, 

I  Propane. 

H 

Pro  perl  ies. — Propane  is  a  colorless  gas  which 
condenses  to  a  liciuid  at  — 18°  C.  Chemically,  it 
seems  more  readily  affected  by  a  few  of  the  reagents 
than  the  preceding  two  hydrocarbons,  but  seems 
very  indifferent  toward  most  of  the  reagents.  Its 
formula  contains  3  carbon  atoms  and  may  be  written 
CH3  —  CH2  —  CH3,  from  which  it  wiU  be  seen  that 
it  contains  at  least  two  methyl  groups. 

BUTANES  (C^Hjo).  Butane  is  a  gas  which  can 
be  prepared  by  treating  2  molecules  of  ethyl  iodid 
with  metallic  sodium  or  zinc.     Thus: 

2CH3CH.,I   +   Na,  =  CH3— CH,— CH3— CH3  + 
2NaI. 
Normal  butane  condenses  to  a  liquid  which  boils  at 

1°  C.    Iso-butane,  ^|^^^CH-CH3,  boilsat-i7°  C. 

Curious  as  it  may  seem,  some  substances  having 
the  same  elements  and  percentage  composition  are 


230  PHARMACEUTIC    CHEMISTRY 

sometimes  different  in  their  nature  and  |)roj)crties. 
Thus,  in  the  synthesis  of  butane,  by  a  slight  difference 
in  the  method  of  its  preparation,  we  obtain  a  com- 
pound which  has  the  formula  C^Hj^,  which,  as  we 
know  is  the  formula  for  butane,  but  whose  boiling- 
point  is  — 17°  C.  Furthermore,  substitution  prod- 
ucts of  these  two  butanes  have  different  properties. 
In  cases  of  this  nature  we  call  this  new  butane  an 
isomer  oj  butane.  Frequently  two,  and  often  more 
substances  having  the  same  percentage  composition 
are  met  with.  These  are  all  spoken  of  as  isomers  of 
the  normal  parent  body,  and  owing  to  this  impor- 
tant property  we  have  the  numerous  organic  com- 
pounds. The  number  of  possible  isomers  increases 
amazingly  as  the  carbon  atoms  in  the  molecule  in- 
crease in  numbers.  Thus,  while  we  have  but  one 
methane  and  one  ethane  and  propane,  we  have  two 
butanes,  three  pentanes,  five  he.xanes,  nine  heptanes, 
eighteen  octanes,  thirty-five  nonanes,  seventy-five 
decanes,  one  hundred  and  fifty-nine  undecanes, 
three  hundred  and  fifty-four  dodecanes,  eighteen 
hundred  and  two  triadecanes.  While  not  all  of 
these  isomerids  of  the  hydrocarbons"  CjjHjg  have 
been  prepared,  it  is  a  fact  that  in  the  case  of  pentane, 
where  three  possibilities  of  isomerism  e.xist,  all  three 
have  actually  been  prepared.  In  the  case  of  he.xane, 
where  five  isomerids  are  possible,  all  five  have  been 
prepared,  and  their  boiling-points  have  been 
determined. 

The   chemical    basis    for    isomerism    is    that    the 
difference  in  pni|)crtics  of  the  different  isomerids  is 


PARAFFINS.  231 

explained  by  a  difference  in  the  arran^remcnt  (A  the 
atoms  in  the  molecule.  In  other  words,  it  is  a 
question  of  the  atomic  arrangement  in  the  molecule. 
Thus,  we  can  determine  the  structure  of  normal 
butane  bv  its  synthesis  from  ethyl  iodid  and  sodium, 
and  prove  it  has  a  straight  chain  of  carbon  atoms. 
Its  graphic  formula  is 
H 

H— C~H  CH3 

!  I 

H— C— H  CH, 

r      •  or  more  1     ^ 

H-C-H       ^^"^P^^tly'       CH, 

I                                        I 
H— C— H,  CH3 

I  normal   butane 

H 

From  the  above  graphic  formula  we  see  that  the 
substance  may  be  termed  diethyl,  CjHj  —  C2H5.  We 
may  also  consider  the  formula  of  normal  butane  to 
be  a  derivative  of  propane  by  attaching  a  carbon 
atom  with  its  saturating  hydrogen  atoms  to  one  of  the 
end  carbon  atoms  of  propane.  There  is,  however,  a 
different  arrangement  possible  in  which  the  four 
carbon  atoms  and  the  ten  hydrogens  form  a  branched 
or  a  forked  chain  and  not  a  straight  one,  according  to 
the  following  graphic  formula: 

I  CH3  CH3 

I  \/ 

H— C— H  ^j.  ^^^^  ^^ 

H3C-C-CH3,       <^°"^P^^tly,  1^^^ 

Jj  iso-butane 


232  PHARMACEUTIC    CHEMISTRY. 

This  second  arrangement  may  be  said  to  be  de- 
rived from  propane  by  attaching  a  fourth  carbon 
atom  to  the  middle  carbon  atom  of  propane.  The 
graphic  formula,  it  will  be  seen,  represents  a  central 
carbon  atom  attached  to  three  methyl  groups,  so  it 
may  be  regarded  as  a  methane  in  which  three  methyl 
groups  are  substituted  for  three  hydrogens.  We 
may  safely  apply  to  it  the  name  of  trimethylmethane, 
CH(CH3)3.  The  above  graphic  formula  agrees 
with  the  synthesis  of  isobutane  from  tertiary  butyl 
iodid  by  reduction: 

(CH3)3CI  +  H,  =  (CH3)3CH  +  HI. 

Therefore,  all  compounds  having  a  forked  or 
branched  chain  are  knoivn  as  iso  compounds,  and  their 
names  are  preceded  with  the  word  "iso." 

The  following  are  three  graphic  formulas  of  the 
isomers  of  pentane: 


H 

H 

1 
H— C- 

-H 

CH3     ^_ 

I 
-C- 

-H 

H— C- 

-H 

1 

CH, 
1          H- 

1 
1 

H 

H— C- 

-H 

, 

-   CH, 

1 

1 

1    '      H- 

-c 

/ 

H— C- 

1 

-H 

c„, 

H— C- 

-H 

•  CH3 

l"^H 

1 

normal 

H 

H 

E 

pentane 
.  P.  37°  C. 
or, 

PARAFFINS. 

H 

I 
H— C— H 

H         I  H 


233 


CH3  CH, 


CH3 

I 


CH 

I 
CH     and 

I 
CH3 

iso-pentane 
B.  P.  30°  C. 


H— C C C— H  H3C— C— CH3 


H— C— H 

I 
H 


I 

H    . .  I 

_CH3 

tetra-methyl- 

methane 
B.  P.  9.5°  C. 


The  above  graphic  formulas  for  pentane  illustrate 
an  important  fact:  that  it  is  possible  to  construct  as 
many  jornmlas  as  there  are  isomerids.  Example:  it 
is  only  possible  to  construct  three  different  graphic 
formulas  for  a  substance  having  the  molecular 
formula  CjH^j,  and  only  three  isomers  of  pentane  are 
known.  More  could  not  be  represented  by  graphic 
formulas,  assuming  always  that  carbon  is  tetravalent. 
This  agreement  between  theoretic  conclusions  and 
observed  facts  strongly  evidences  the  tetravalent 
character  of  carbon. 

The  Nomenclature  oj  the  Isomeric  Paraffins. — In 
the  case  of  the  different  isomers,  different  distinguish- 
ing terms  are  employed;  thus,  normal,  iso  and  neo- 
paraffins.  To  illustrate:  in  a  normal,  sometimes 
called  primary,  paraffin,  a  straight  carbon  chain 
exists  in  which  each  middle  carbon  atom  is  at- 
tached to  two  other  carbon  atoms  and  two  hydrogen 
atoms.     It  may  be  said  that  normal  paraffins  con- 


234 


PHARMACEUTIC    CHEMISTRY 


tain  the  ^^vnu\)  =  CH^,  which  is  sometimes  called 
priuuiyy  group. 

An  /.s()- paraffin  contains  at  least  one  carbon  atom 
united  directly  with  three  other  carl)()n  atoms  and 
contains  the  group  EE  CH,  sometimes  called  the 
secondary  group. 

A  neo-paraffiu,  sometimes  called  tertiary  paraffin, 
contains  at  least  one  carbon  atom  directly  combined 
with  four  others,  and  contains  the  group  =  C,  also 
termed  a  tertiary  group. 

Below  are  given  graphically  the  three  groups 
characteristic  of  the  three  classes  of  paraffins,  and 
following  these,  three  examples  of  paraffins  repre- 
senting each  class: 


CHo 

I 


primary  group 

of  a 
normal  paraffin 
CH3 

I 
CH.. 

I 

CH3 


propane, 
a 


CH 

I 


secondary  group 

of  an 

iso-paraffin 

CH3CH3 


CH 

I 
CH3 

iso-butane, 
a 


normal  {)araffin,  secondary  paraffin, 
(methyl  ethane)    (trimethyl  methane) 


tertiary  group 

of  a 
neo-paraffin 
CH3 
j 
H3C— C— CH3 

I 
CH3 

a  tertiary  paraffin 

(tttra-methyl- 

methane) 


In  the  case  of  the  "  iso "  and  the  "tertiary" 
hydrocarbons,  it  is  sometimes  convenient  to  use  a 
name    which    often   e.\i)resses   readilv    the   constilu- 


PARAFFINS.  235 

tion  of  a   compound   (examine  the  names  given  in 
brackets). 

Isomerism  is  oj  two  kinds:  (i)  Metamerism. — 
Substances  which  have  the  same  percentage  com- 
position and  the  same  molecular  weight  are  said  to 
be  metameric.  Thus,  the  formula  CjHgO  is  charac- 
teristic of  both  ethyl  alcohol  and  methyl  ether. 
These  substances,  therefore,  are  metameric.  (2) 
Polymerism. — Substances  which  have  the  same  per- 
centage composition,  but  different  molecular  weights,- 
are  said  to  be  polymeric.  Thus,  CoH^O  is  the 
formula  of  aldehyd;  this  formula  multiplied  by  3  will 
give  us  CeHj203,  which  is  the  formula  for  paraldehyd. 
Again,  acetylene  has  the  formula  C2H2;  benzene, 
CgHe,  and  styrene,  CgHg.  These,  therefore,  being 
multiples  of  acetylene,  are  polymeric. 

(i)  Metamerism  is  shown  thus,  CjHeO,  may  e.xist 
as  a  or  as  h: 

CH3  CH3 

I  ~  I 

CH2qH  o 

ethyl  alcohol  | 


methyl  (ether)  oxid. 
(2)  Polymerism  is  shown  in  paraldehvd,  which  is 
a  multiple  of  aldehvd,  C,H,0 : 
CH3 

'  /-O    multrplied       '       '- ^^^^ 

^\H         by  3  gives  paraldehyd 

aldehyd 
Acetylene  formula  multiplied  bv  4  gives 

QHg  *  CsHg^ 

acetylene  styrene 


236  PHARMACEUTIC    CHEMISTRY, 

FORMULAS. 

While  symbols  are  used  to  express  atoms,  formulas 
are  used  to  express  molecules.  Formulas  are  of 
three  kinds:  (i)  the  empiric  formula,  which  rcjjrc- 
sents  the  elements  present  in  a  compound  and  the 
relative  proportion  of  each.  Thus,  the  formula 
C2HQO  may  indicate  either  a  compound  having  the 
formula  C^HjjOj  or  one  having  the  formula  C^H^^O^, 
etc.  If,  by  the  determination  of  its  vapor  density, 
we  find  it  to  be  C^HjjO.^,  in  such  a  case  the  formula 
showing  the  number  of  atoms  in  the  molecule  (ind 
their  relative  numbers  is  called  molecithn  formula. 
(2)  Rational  formula,  also  caWedconslitutional  formula 
indicates  the  probable  arrangement  exhibited  in  the 
formula;  also  by  a  characteristic  group  present,  the 
class  the  compound  belongs  to.  (3)  Graphic  for- 
mula, also  called  structural  formula,  represents 
the  arrangement  of  the  atoms  in  a  molecule  and  the 
probable  relations  of  one  to  another.     Examples: 

Empiric  formula.     Rational  formula.     Graphic  formula. 
(constitutional  )  (structural.) 

H 
■        I 
CHr.O  C,H,OH  H— C— H 

I 
alcohol  alcohol  H— C— OH 

I 

H 
alcohol 


CHAPTER  XXII. 
ETHYLENE  SERIES. 

The  second  of  the  series  of  hydrocarbons  is  the 
ethylene  series,  so  called  from  the  first  member  of  the 
series.  This  series  is  sometimes  called  the  "ethene 
series"  or  the  "olefins."  The  general  formula  of 
the  series  is  C„H2jj.  Whereas,  in  the  paraffin  series 
we  cannot  form  the  halogen  derivatives  without  sub- 
stituting one  or  more  hydrogen  atoms  of  the  paraf- 
fins, in  the  ethylene  series  we  can  form  addition 
products  directly  without  substituting  the  hydrogen 
atoms  in  the  molecule.  Therefore,  we  call  the 
methane  series  saturated  because  they  cannot  unite 
directly  with  elements  or  compounds;  whereas  the 
ethylene  series  of  hydrocarbons,  because  they  do 
combine  directly  with  other  elements  or  compounds, 
we  call  unsaturated.  This  unsaturation  depends  on 
the  difference  in  the  relation  between  the  carbon 
atoms.  Thus,  in  the  case  of  ethane,  we  find  it  to  be 
composed  of  two  methyl  groups  which,  when  united, 
again  form  a  saturated  hydrocarbon  with  no  free 
bonds.  The  two  methyls  are  united  by  one  bond. 
This  bond  which,  in  a  former  chapter  we  called  the 
paraffinic  bond,  is  very  strong  and  tenaciously  resists 
any  attempt  to  break  it  up.  In  the  case  of  the 
olefins,  we  find  the  carbons  united  by  a  double  bond 
which  we  have  previously  called  the  olefinic  bond. 
Now,  one  would  supjjose  that  the  carbon  atoms, 
237 


238  PHARMACEUTIC    CHEMISTRY. 

being  united  by  two  bonds  would  form  much 
stronger  union  in  the  case  of  the  olefins  than  they 
would  in  the  case  of  the  paraffins,  where  but  single 
bond  union  exists.  Such,  however,  is  not  the  case. 
The  paraffinic  bond  is  much  stronger  than  the  olefinic. 
The  relation  of  the  carbon  atoms  in  the  ethylene 
series  is  usually  represented  in  the  graphic  formulas 
by  two  bonds.  The  following  are  the  first  six 
members  of  the  ethylene  series  with  their  empiric  and 
graphic  formulas: 


TABLE 

OF    THE    OLEFINS. 

(c„n.n-) 

Name. 

Mol.  Form. 

Mol.  Wt.         B.  Pi.      C 

Ethylene, 

C.H, 

28            — ro3°  C. 

Propylene, 

C,Hf, 

42           —48.5°  C. 

Butylcne,  C4H8  56  —5.°  C. 


CHa 

II 
CH, 

CH, 

II 
CH 

I 

qH,5 

II 

CH 

I 

CH, 

I 
CH3 

CH, 

II 
CH 

Amylcne,  CjH.o  70  40.°  C.  CHj 

! 

CH, 

I 
CH3, 


OLEFINS. 

239 

Mol.  Form. 

Mol.  Wt. 

B.Pt. 

Graph.  Form. 
CH, 

II 
CH 

C0H13 

84 

68.°  C. 

1 
CH, 

1 
CH, 

1 
CH3 

Hex3'lenc, 


Chemical  Properties  oj  the  Olefins. — The  olefins 
unite  directly  with  other  substances,  particularly  the 
halogens  and  the  hydracids.  The  members  of  the 
series  are  homologous  and  differ  from  one  another  by 
the  group  CHj.  They  are  also  polymeric ;  they  bear 
a  simple  ratio  to  the  paraffins,  each  member  contain- 
ing two  hydrogen  atoms  less  than  the  paraffin  hav- 
ing a  corresponding  number  of  carbon  atoms.  They 
likewise  bear  a  simple  relation  to  each  other  in  point 
of  their  molecular  weights.  Thus,  the  members 
differ  from  one  another  in  their  molecular  weights  by 
14.  The  chemical  properties  of.  ethylene  apply  to 
the  whole  group.  Thus,  with  bromin  they  form 
bvomethylenes,  with  hydrogen  they  form  the  cor- 
responding paraffins,  and  with  halid  acids  they  form 
the  monohalogen  derivatives  of  the  paraffins. 

Ethylene,  CjH^,  also  called  olefin,  olefiant  gas 
(so  called  from  oleum,  oil,  and  jians,  forming;  be- 
cause with  the  halogens  it  forms  oily  liquids)  and 
ethene;  it  is  the  first  member  of  the  series  of  that 
name.  One  would  suppose  that,  in  order  to  cor- 
respond to  the  paraffins,  methylene,  CHj,  ought  to  be 
the  first  member  of  this  series,  but  all  attempts  to 


240  PHARMACEUTIC    CHEMISTRY. 

synthetize  or  isolate  such  a  compound  have  been  un- 
successful. Yet  a  number  of  important  compounds, 
such  as  carbon  monoxid  and  hydrocyanic  acid,  are 
sometimes  considered  as  the  derivatives  of  methylene. 

Preparation. — (i)  Ethylene  is  best  prepared  by  mix- 
ing ethyl  alcohol  with  strong  sulfuric  acid  and  heating 
the  mixture  to  175°  C.  Two  reactions  occur,  the 
first  one  forming  ethyl  sulfuric  acid,  with  the  elimina- 
tion of  water;  the  second  one  forming  ethylene,  with 
the  elimination  of  sulfuric  acid,  according  to  the 
following  equations: 

C2H5OH    +    H^SO,    -    C2H5HSO,    +    H3O. 

C2H5HSO,   -   C3H,   +   H2SO4. 

(2)  It.  may  be  prepared  by  decomposition  of  the 
monohalid  derivatives  of  ethane  by  alcoholic  solu- 
tion of  an  alkalin  hydroxid.  This  is  a  very  im- 
portant reaction  for  the  preparation  of  the  homo- 
logues  of  the  ethylene  series.  Thus,  any  paraffin 
alkyl  halid,  by  treating  it  with  alcoholic  solution  of 
potassium  hydroxid,  will  decompose  into  hydro- 
bromic  acid  and  form  the  corresponding  homologue 
of  ethylene.     Reaction: 

QH.Br  +   KOH  =   KBr  +  H/)   +  CH,. 

Properties. — Ethylene  is  a  colorless  gas  having  a 
peculiar,  disagreeable  odor,  burns  with  a  luminous, 
smoky  llame;  with  air  and  oxygen  it  forms  explosive 
mixtures;  it  is  irrespirable  and  is  an  important  con- 
stituent of  illuminating  gas,  the  luminosity  of  which 
depends  greatly  upon  the  amount  of  ethylene  it  con- 
tains. It  unites  directly  with  chlorin,  volume  for 
volume,    forming    an    oily    liquid    having    the    coxw- 


OLEFINS.  241 

position  C2H4CI2,  ethylene  dichlorid,  commonly 
known  as  "Dutch  liquid,"  owing  to  its  having  been 
discovered  by  four  Dutch  chemists. 

Besides  ethylene  chlorid,  the  other  halid  deriva- 
tives are:  ethylene  bromid,  C2H^Br2,  and  ethylene 
iodid,  C2H4I2. 

Physical  Properties. — In  point  of  aggregation,  the 
olefin  series  is  very  similar  to  the  paraffins.  Thus, 
the  first  jour  members  are  gases,  the  next  thirteen  are 
liquids  and  the  remainder  are  colorless  solids.  The 
first  two  members  have  no  isomers,  but  there  are 
three  isomeric  butylenes,  four  isomeric  amylenes  six 
heptylenes,  six  octylenes  and  two  nonylenes,  all  of 
which  have  been  prepared. 

Of  the  amylenes,   isoamylene,   trimethylethylene, 
commonly  known  as  pental,  has  the  formula 
CH3  CH3 


CH 

I 


It  is  prepared,  like  the  other  olefins,  by  dehydrating 

isopentyl  alcohol  according  to  the  following  formula: 

CH3  CH3  CH3  CH3 

\  /  \/ 

C— OH  C  +  H2O 

I  -        II 

CH2  CH 

I  I 

CH3  CH3 

Pental  has  been  used  successfully  as  an  anesthetic. 

16 


242  PHARMACEUTIC    CHEMISTRY.. 

Structure  oj  Ethylene. — Three  theoretic  formulas 

have  been  assigned  for  ethylene: 

H 

I  I 

H— C— H  H— C— H  H— C— H 

I  --  I  -  il 

H— C— H  C  H— C— H 

I  I 

H 

(i)  (2)  (3) 

Of  these  the  first  formula,  representing  carbon  atoms 
as  practically  trivalent  and  showing  the  two  free 
bonds,  would  seem  to  be  the  most  probable.  If  this 
were  the  true  structure  of  ethylene,  the  independent 
existence  of  the  alkyls,  methyl,  ethyl  or  propyl,  etc., 
would  also  seem  possible.  This,  however,  is  not  the 
case.  The  same  difficulty  seems  to  hold  with  the 
second  formula.  The  third  formula,  therefore, 
most  probal^ly  expresses  the  true  structure  of  ethy- 
lene. 

Nomenclature. — The  names  of  the  olefins  cor- 
respond to  the  names  of  the  paraffins,  with  the  ex- 
ception that  the  vowel  "a"  of  the  first  series  has  been 
replaced  by  the  vowel  "e.  " 

ACETYLENE  SERIES. 

Acetylene,  C2H,,  also  called  cthine,  is  the  first 
member  of  the  third  series  of  hydrocarbons,  and 
after  it  the  scries  has  been  named.  In  this  series  the 
carbon  atoms  are  linked  l)\-  three  bonds.  The 
general  formula  of  the  .series  is  C'„H^„._o.     They  are 


ACETYLENES.  243 

unsaturated  and  unite  directly  with  four  atoms  of  the 
halogens  or  with  two  molecules  of  the  haloid  acids 
without  any  loss  of  hydrogen,  and  through  such  ad- 
dition are  converted  into  substitution  products  of  the 
paraffins.  Their  structural  formula  shows  them  to 
contain  at  least  one  CH  group.  This  group,  when 
it  is  adjacent  to  the  acetylenic  bond  (triple  bond), 
always  precipitates  ammoniacal  solutions  of  silver 
nitrate,  which  no  other  hydrocarbon  will  do. 

THE   ACETYLENES. 

(CnH,n_3.) 

Name.  Mot.  Form.         B.  Pi.       ^''^'P^'j'^ 

rormnla_ 

C— H 


Acetylene  (or  ethine),  C.H^  —84°  C. 


C— H. 
C— H 


Allylene  (methyl  acetylene,  |j| 

propine),  C3H4  gas  C 

C=H3. 
C— H 

III 

C 

Crotonylene  (ethyl  acetylene,  | 

and  butine),       C4H6  18°  C.        C^H^ 

! 
C=H3. 

CH 


Valerylene  (propyl  acetylene  | 

or  pentine),  CsHg     45  to  50°  C.         C=H, 

C=H3 
I 
C=H, 


244  PHARMACEUTIC    CHEMISTRY. 

Preparation  and  Properties. — (i)  By  the  action  of 
calcium  carbid  on  water: 

CaCj  +   2H2O   =   Ca(OH),  +  QH,. 

(2)  By  the  direct  union  of  the  elements,  such  as 
occurs  on  passing  electric  sparks  between  carbon 
electrodes  in  the  presence  of  hydrogen: 

2C  +  H2  =  QH,,. 

(3)  ^y  passing  chloroform  vapor  over  red-hot 
copper: 

2CHCI3    +    3CU3    =    C3H,    +   3CU2CI2. 

The  first  method  is  important  commercially  because 
it  is  employed  in  the  manufacture  of  acetylene  gas 
for  illuminating  purposes.  The  structural  formula 
of  acetylene  shows  the  carbon  atoms  to 'be  linked  by 
three  bonds.  The  significance  of  this  "acetylenic" 
bond  is  not  clear  at  the  present  time.  This  bond  is 
very  unstable  as  the  nature  of  acetylene  proves.  The 
gas  cannot  be  stored  under  pressure,  and  in  the 
liquefied  form  it  is  not  valued  commercially.  When 
heated  sufficiently,  high  acetylene  forms  the  poly- 
meric benzene,  CgHg,  and  styrene,  CgHg.  It  unites 
directly  with  the  halogens,  especially  bromin  and 
hydrobromic  acid,  forming  tetrabromethane  and 
ethyl  bromid. 

Nomenclature. — Compounds  having  the  triple 
union  have  names  ending  in  "ine."  Thus  the  third 
member  is  oflicially  called  "propine. "  In  tlu- 
{)resent  work,  however,  we  have  adhered  to  the  oldcr 
and  better  understood  nomenclature.  This  series  con- 
tributes two  acids  of  pharmaceutical  interest,  namely 
cn.tonir  acid.  (',H„(),.  and  oleic  acid,  C.^H.,, ()._,. 


GAS.  245 

COAL  GAS. 

Coal  gas  is  produced  by  subjecting  coal  to  ''dry'" 
or  ''destructive"  distillation. 

Destructive  distillation  consists  in  heating  a  non- 
volatile organic  matter  (coal  or  wood)  in  such  a 
manner  that  air  is  excluded  and  the  organic  body  is 
decomposed,  giving  rise  to  new  compounds — prod- 
ucts  of  decomposition. 

Coal  gas,  therefore,  is  a  mixture  of  gases  (pro- 
ducts of  the  decomposition  of  coal),  consisting  mainly 
of  hydrogen  and  the  hydrocarbons.  Coal  is  heated 
in  iron  retorts  without  contact  of  air,  and  the  pro- 
ducts of  decomposition  are  cooled  in  condensers, 
where  the  heavy  coal-tar  and  the  lighter  gas-liquor 
properly  cooled  are  collected  in  tanks.  The  gas 
which  remains  uncondensed  is  passed  through  tanks 
tilled  with  wetted  coke  for  the  purpose  of  dissolving 
the  ammonia.  Next  the  gas  is  led  through  cham- 
bers containing  either  ferric  hydroxid  or  slaked  lime, 
spread  upon  shelves  for  the  purpose  of  ridding  the 
gas  of  sulfurated  gases,  such  as  carbon  disulfid, 
hydrogen  sulfid,  ammonium  sulfid,  etc.  When 
slaked  lime  is  employed  as  a  purifying  agent  it  ab- 
sorbs carbon  dioxid  as  well.  The  gas  so  purified  is 
finally  stored  in  large  gas  tanks. 

COMPOSITION  OF  COAL  GAS. 

Hydrogen,  ]  52%  by  volume.  These  three  gases  serve  as 
Methane,  {-      34%  "         "  diluents  of  the  heavy  hy- 

Carbonic  oxid,  J        6%  "         "  drocarbon      illuminants 

and      preclude      smoky 

flames. 


246  PHARMACEUTIC    CHKMISTRV. 

Ethylene   1  or  ^          y  These  three  gases  are  the 

Acetylene  >  4%  bv  vo  umc  ■„       ■       ,  °.           , 

„      •'  t/ti    .  lUiimiuants  in  coal  k^s. 

Benzene    J  "^ 

Ammonia  gas  \ 

Nitrogen  [      <>,   ,1      ^  These  four  gases  are  the 

Carbon  disuilid  {  usual  impurities  of  gas. 

Carbon  dioxid  J 

It  will  be  seen  from  the  above  analysis  that  the 
"diluents"  constitute  about  90%  of  coal  gas,  while 
the  "luminants,"  rich  in  carbon  and  to  which  the 
luminosity  of  the  flame  is  due,  constitute  but  4%  by 
volume  of  the  gas.  The  impurities  are  due  to 
nitrogen  (a  product  of  decomposed  air  which  en- 
ters the  retorts  in  the  process  of  charging  them), 
ammonia,  carbon  dioxid  and  the  sulfids  which  es- 
cape the  purifiers. 

STRUCTURE  OF  GAS  FLAME. 

A  gas  flame  may  be  said  to  consist  of  three  layers: 
the  innermost  layer  consisting  of  unburnt  gases; 
the  middle  layer  or  luminous  layer,  consisting  of 
partially  burnt  gases  and  minute  particles  of  carbon, 
which  latter  impart  to  the  flame  its  reducing  proper- 
ties and  the  name  "reducing  flame"  (R.  F.);  the 
outermost  layer  which  is  colorless,  consisting  of 
completely  burnt  gases.  This  layer  in  which  the 
carbon  and  hydrogen  are  completely  oxidized  is  the 
hottest  of  the  three  and  is  called  the  "oxidizing 
flame"  (O.  F.). 

The  innermost  flame,  therefore,  is  a  mixture  of 
gas  and  air,  the  middle  layer  to  which  the  oxygen  of 
the  air,   owing  to  the  great   heat  of  the  oxidizing 


GAS    FLAME.  247 

flame,  has  no  access,  consists  of  partly  l)urnt  hydro- 
carbons with  particles  of  carbon  rendered  incandes- 
cent so  as  to  emit  white  light.  Free  carbon  can  be 
detected  in  this  layer  by  introducing  a  piece  of  white 
porcelain  into  the  flame  when  the  carbon  will  de- 
posit on  it  as  soot. 

In  the  outermost  layer  the  hydrocarbons  are 
"oxidized"  or  "burnt  "  to  carbon  dioxid  and  water. 
This,  therefore,  is  the  "hottest"  flame. 

If  air  is  mixed  with  gas  before  its  ignition,  as  in  the 
case  of  the  "Bunsen  burner,"  both  the  carbon  and 
hydrogen  become  completely  "burnt  up,"  furnishing 
a  colorless  or  "  Bunsen  flame."  A  Bunsen  burner 
consists  of  a  gas-jet,  the  base  of  which  is  provided 
with  a  perforated  collar  which  admits  the  air  into  the 
jet. 

The  temperature  of  gas  flame  is  very  high,  that  of  a 
flat  burner  about  1300°  C,  and  that  of  a  Bunsen 
burner  about  1500°  C. 

The  "Welsbach  incandescent  burner"  has  ef- 
fected an  enormous  economy  in  gas  consumption. 
Thus,  the  86%  of  hydrogen  and  methane  present  in 
gas,  and  Vv^hich  in  the  ordinary  burner  produce 
barely  any  light,  is  utilized  in  rendering  the  infusible 
mantle  of  the  incandescent  burner  hot,  and  thus 
produce  a  strong  white  light. 


CHAPTER  XXIII. 

DERIVATIVES  OF  METHANE. 

The  structural  formula  of  methane,  CH^,  is  the 

following: 

H 

I  I 

— C—    —     H~C— H 

I  I 

carbon  skeleton  H 

If  one  of  the  hydrogen  atoms  is  substituted  by  an 

atom  of  any  other  univalent  element  or  a  univalent 

group  of  elements,  a  "mono-substitution"  derivative 

is  produced.     Thus,  by  substituting  the  hydrogen 

atoms  of  methane  with  the  halogens  the  following 

derivatives  are  obtained: 

H  H  H 

I  I  I 

H— C— CI         H— C— Br  H— C— I 

I  1  I 

H  H  H 

methyl  chlorid       methyl  bromid  methyl  iodid 

If  two  hydrogens  of  methane  are  replaced  by  two 

univalent  or  one  divalent  atom  or  group,  a  "disubsti- 

tution"  product  is  obtained;  thus: 

H  H  H 

I  1  I 

H— C— CI         H— C— Br         H— C— I 

1  1  I 

CI Hr  1 

methylene  chlorid  methylene  bromid  methylene  iodid 

(dichlormethane)    (dibrommethane)  (diiodomethane) 

248 


MKTHANE    DKEIVATIVES.  24Q 

If  three  hydrogen  atoms  in  methane  are  substituted 
by  three  monads,  or  one  dyad  and  one  monad,  or  by  a 
triad  atom  or  group,  a  "trisubstitution"  product  is 
obtained : 

H 

I 
CI— C— CI 


CI 


methenyl  chlorid  (or  chloroform) 


If  all  of  the  hydrogen  of  methane  is  substituted  by 
other  atoms  or  groups  of  atoms,  "tetfa-substitution  " 
products  are  obtained: 


CI 

Br 

I 

CI— C— CI 

Br— C— Br 

I— C— I 

1 
CI 

Br 

I 

carbon  tetrachlorid. 

carbon  tetrabromid. 

carbon  tetraiodid. 

tetra-chlor-methane)   (tetra-brom-methane)   (tetra-iodo-methane) 

Of  the  above  halogen  derivatives  only  the  tri-  and 
tetrasubstitution  products  are  of  practical  importance 
to  pharmacy  and  the  arts. 

CHLOROFORM.— Trichlormethane(chloroformum 
U.  S.  P.)— CHCI3  (Souberain  and  Liebig,  183 1)  is 
prepared  by  heating  a  mixture  of  chlorinated  lime 
(calx  chlorinata),  alcohol  and  water.  The  mixture 
when  distilled  yields  chloroform  which  passes  over 
with  the  water-vapor  and  is  condensed  together  with 
the  water,  from  which  it  separates  owing  to  its  higher 
specific  gravity.     It  is  then  redistilled  from  calcium 


250  PHARMACEUTIC    CHEMISTRY. 

chlorid  which  absorbs  the  water.  Tlie  reaction  is 
very  complex,  and  it  is  su[j|>osed  that  three  changes 
occur  in  its  formation.  The  hrst  change  depends 
upon  the  oxygen  in  the  bleaching  powder  which  con- 
verts the  alcohol  into  aldehyd;  the  second  change 
depends  upon  the  action  of  chlorin  on  the  alcohol 
and  the  formation  of  chloral;  the  third,  upon  the 
decomposition  of  the  chloral  by  the  alkalin  lime 
(of  the  bleaching  powder)  into  chloroform  and 
calcium  formate.     To  illustrate: 

(0 


(2) 


CH, 

1 

CH3 

+  0=     1         +  H^O 

CH3OH               CHO 

alcoho 

1                          aldehyd 

CH3 

CCI3 

+  3C1,=  1          +   3HCI 

CHO 

CHO 

chloral 
(trichloraldehyd) 

f  CCI3 

i    1 

+  Ca(OH)2  =  2CHCl3  + 

CaCCHO^)^ 

CHO 

slaked  lime       chloroform 

calcium  formate 

(3) 


Lately  the  production  of  chloroform  from  acetone 
has  almost  entirely  superseded  the  process  just  given. 
This  latter  process  depends  upon  the  formation  of 
trichloracetone  which,  u])on  being  heated  with 
lime,  is  converted  into  chloroform  and  calcium 
acetate;  thus: 

C=H3  C=Cl3 

C=0     +     3Cb      =      C  =  0     +      ^HCland 

I  I 

C=H3  C=H3 

acetone  trichloracetone 


METHANE    DERIVATIVES.  25: 


H  C=C1, 


Ca— O     +     C=0      =     Ca— O— C  =  0     +     CHCl., 
lime  I  I  chloroform 

[{h  molecule)]       CH3  CH, 

calcium  acetate 

Description,  Uses  and  Tests. — Chloroform  is  a  color- 
less, heavy-thin  (limpid)  liquid,  having  a  sweetish 
taste  and  a  characteristic  (chloroformic)  odor.  The 
specific  gravity  of  pure  chloroform  is  1.525.  The 
official  variety,  containing  a  little  alcohol  for  the  pur- 
pose of  preservation,  has  a  specific  gravity  of  1.497 
and  a  boiling-point  of  61°  C.  It  is  readily  soluble 
in  alcohol  (constituting  the  official  spirit),  ether,  etc., 
and  to  the  extent  of  0.5%  in  water  (1:200),  forming 
the  official  chloroform  water  (aqua  chloroformi 
U.  S.  P.).  It  ignites  with  difficulty  and  Ijurns  with 
a  greenish,  smoky  flame. 

Chloroform  is  used  as  a  solvent  for  fats,  resins, 
caoutchouc,  phosphorus,  sulfur  and  iodin.  The 
commercial  variety  contains  aldehyd,  alcohol,  etc., 
from  which  it  can  be  purified  by  mi.xing  it  with 
sulfuric  acid,  separating  from  this  acid,  neutralizing 
with  a  solution  of  sodium  carbonate,  separating 
from  this  solution,  adding  lime  to  dehydrate  it  and 
finally  distilling  it  on  a  water-bath,  adding  to  the 
distillate  from  one-half  to  one  per  cent,  of  alcohol  to 
prevent  the  formation  of  its  impurity,  carbonyl 
chlorid  (COClj),  so-called  phosgene  gas. 

/CI 
CHCI3    -1-    O    =    CO    +    HCl. 

\C1 


252  IMIAKMACKl'TIC    CHEMISTRY. 

Tests  jor  Purity. — Pure  chlorofonii  should  not 
color  solution  of  sulfuric  acid  and  chromic  oxid 
green,  nor  should  it  discolor  solutions  of  KOH,  KI 
or  H2SO4.  It  should  not  precipitate  silver  nitrate. 
In  medicine  chloroform  is  extensively  used  as  an 
anesthetic  (Simpson,  1848).  For  this  purpose  it 
should  never  be  administered  in  a  room  illuminated 
with  gas,  because  the  traces  of  CO  which  escape 
combustion,  at  once  combine  with  the  chloroform 
forming  the  strongly  irritating  and  irrespirable 
phosgene  gas.  As  an  anesthetic  it  is  safer  for  chil- 
dren and  women  in  parturition  than  for  other  adults. 
Externally  it  is  an  irritant  or  vesicant. 

Tests. — -(i)  Chloroform  in  solutions  may  be 
detected  by  warming  together  some  of  it  with 
alcohol,  solution  of  sodium  hydroxid  and  a  few  drops 
of  anilin,  when  a  strong,  irritating  and  poisonous 
vapor  of  phenyl-isocyanid  is  produced: 

CHCI3  +  C,H,.NH3  +  3NaOH  =  (C.HQ  NC  + 

""""      anilin  phenyl-isocyanid 

3KCI   +  3H3O. 

(2)  Heated  with  an  alcoholic  solutionx)f  potassium 
hydroxid    (saponified),  it    gives   potassium    formate 
and  chlorid: 
CHCl,  +  4K()H  =  HCOOK  +  3KCI  +  2H,0. 


(3)  Chloroform  reduces  "Fehling's  solution" 
readily,  precipitating  red  cuprous  oxid: 

CHCI3  +  2Cu()  +  5KOH  =  Cu.O  +  K,C03  + 
3KCI  +  3H,(). 


METHANE    DERIVATIVES.  253 

(4)  When  chloroform  is  mixed  with  a  solution  uf 
betanaphthol  in  strong  potassium  hydroxid  and  the 
liquid  heated  to  about  50°  C,  a  dark  blue  color  is 
produced,  which  gradually  changes  to  green  and 
fmally  to  brown. 

CARBON  TETRACHLORID.—Tetrachlormethanc, 
CCI4,  is  produced  by  the  action  of  chlorin  on  carbon 
disulfid  or  on  chloroform  (Regnault,  1840). 

(i)   CS2  +  3a  =  „<^cii_  +  s,cu. 

carbon  carbon 

disulfid  tetrachlorid 

The  two  products  of  the  reaction  are  separated  by 
distillation. 

(2)   CHCI3  +  CU_  =  CCl,  +  HCl. 

Properties,  Uses  and  Tests.— Ca.rhon  tetrachlorid 
is  a  heavy,  colorless  liquid  which  boils  at  77°  C. 
Heated  with  water  to  250°  C,  it  decomposes  into 
carbon  monoxid  and  hydrochloric  acid.  Its  specific 
gravity  is  1.593  (20°),  and  it  should  be  noted  that  the 
polychlor  derivatives  have  a  high  specific  gravity, 
and  that  the  corresponding  brom-  and  iodo-deriva- 
tives  are  even  heavier  than  the  chlor-products. 
Carbon  tetrachlorid  (carbona)  is  non  inflammable 
and  can  be  used  as  a  fire  extinguisher.  Like  petro- 
Icum-benzin,  the  odor  of  which  it  similates,  it  is  used 
in  extracting  fats  from  refuse  materials,  in  cleansing 
stained  or  soiled  fabrics  and  as  a  solvent  in  organic 
chlorinations,  it  being  unaffected  by  chlorin. 

BROMOFORM. — Tribrommethane  (bromoformum 
U.  S.  P.),  CHBrg  (Lowig,  1832).  The  commercial 
bromoform  consists  of  g(f:'^:  of  tribrommethane  and 


254  PHARMACEUTIC    CHEMISTRY. 

1%  of  alcohol.  It  is  prepared  by  methods  analogous 
to  the  production  of  chloroform,  or  by  direct  bromi- 
nation  of  ethyl  alcohol  dissolved  in  an  aqueous  .solu- 
tion of  potassium  hydro.xid,  until  the  latter  begins 
to  acquire  the  color  of  bromin.  It  is  purified  in  a 
similar  manner  to  chloroform,  which  it  resembles  in 
odor  and  appearance. 

Properties  and  Uses. — Bromoform  is  a  colorless 
liquid,  having  a  specific  gravity  of  2.9  (17°)  and  boil- 
ing at  151°  C.  It  is  freely  soluble  in  alcohol  and 
ether,  but  sparingly  so  in  water.  It  is  used  in 
medicine  as  an  anesthetic,  antispasmodic  and  seda- 
tive; exhibited  in  a  hydroalcoholic  solution  or  emul- 
sion. 

IODOFORM.  —  Triiodomethane  (iodoformum 
U.  S.  P.),  CHI3  (Serullas,  1822).  It  is  prepared  by 
precipitating  a  solution  of  iodin  in  potassium  iodid 
with  alcohol  or  acetone  in  the  presence  of  an  alkali 
carbonate  or.  hydroxid.  The  yellow  powder  thus 
produced  can  be  purified  by  crystallization  from 
alcohol  (he.xagonal  crystals),  or  by  sublimation 
(golden  yellow  leaflets).     Reaction: 

QH^OH    +    4I,  +  3KXO3  =  CHI3  +  5KI   -K 

ethyl  alcohol 
3CO2   +    2H2O   +    KCHO2. 

Properties,  Uses  and  Tests. — Iodoform  melts  at 
119°  C,  is  slightly  soluble  in  water,  readily  in  alcohol, 
ether,  chloroform,  benzin,  carbon  di.sulfid,  fixed  and 
volatile  oils.  It  has  a  strong  antiseptic  and  anes- 
thetic action  (depending  on  the  96.6%  of  iodin  it 
contains),   and   is  used  as  a  dressing  in  surgery.     It 


ETHANE    DERIVATIVES.  255 

possesses  a  strong,  aromatic,  saffron-like  odor,  which 
can  be  masked  by  traces  of  cumarin,  vanillin,  naph- 
thalin  or  oil  of  bergamot.  Its  chief  adulterant  is 
picric  acid  which  may  be  detected  by  agitating  the 
sample  with  a  solution  of  KOH,  carefully  neutralizing 
with  acetic  acid;  upon  adding  KNO3,  a  yellow  pre- 
cipitate of  potassium  picrate  is  deposited.  A  water 
solution  of  iodoform  should  not  yield  a  precipitate 
with  BaClj  (sulfates)  or  with  AgNOj  (chlorids). 

Iodoform  is  hydrolyzed  by  alcoholic  potash  in  a 
similar  manner  to  chloroform.  When  heated  with 
zinc  dust  and  water,  iodin  is  evolved  and  methane 
formed;  thus: 

2CHI3  +  3Zn.  +  3H2O  =3Znl2+  sZnO  +  2  CH,. 

CARBON   TETRAIODID.— CI,,  was  at  one  time 
introduced  as  "odorless  iodoform."     It  is  prepared 
in  a  manner  similar  to  carbon  tetrachlorid.    • 
DERIVATIVES  OF  ETHANE. 

Under  Methane  we  have  seen  that  by  a  process  of 
gradual  substitution  of  chlorin  for  the  hydrogen  of 
marsh  gas,  we  have  changed  it  into  carbon  tetra- 
chlorid: 

H  H  H 

I  1  I 

H— C— H  —  H— C— CI  -^  H— C— CI  -> 

I  I  I 

H  H  CI 

H  CI 

I  I 

CI— C— CI  —  CI— C— CI 

I  I 

CI  CI 


256  PHARMACEUTIC    CHEMISTRY. 

In  a  like  manner,  bromin,  iodin  and  other  mono-, 
di-,  tri-,  and  tetra-substitution  products  may  be 
formed  from  methane  as  well  as  other  hydrocarbons. 
Thus,  from  ethane  we  may  get  the  following: 

H  H  H 

I  I  I 

H— C— H  H— C— H  H— C— H 

I  -.  I  -  I  -^    etc. 

H— C— H  H— C— CI  H— C— CI 

I                           I                            I 
H  H  Cl^ 

ethyl  chlorid         "ethylidene  chlorid" 
(dichlorethane) 

The  halogen  derivatives  of  ethane  are  less  important 
and  interesting  than  those  of  methane. 

CH, 
ETHYL  CHLORID,    |  ,  is  a  limpid,  colorless 

CH2CI 
liquid,  boiling  at  12.5°  C.  It  burns  with  a  greenish, 
smoky  flame,  is  jjut  sparingly  soluble  in  water,  but 
freely  in  alcohol  (this  solution  is  called  "chloric 
ether")  and  ether,  etc.  When  heated  with  potas- 
sium hydro.xid,  it  forms  alcohol: 

C2H5CI    +    KOH    =    KCl    +    C2H5OH. 
When  it  is  treated  with  chlorin  in  direct  sunlight,  it 
yields  the  di-,  tri-,  tetra-,  etc.,  substitution  products 
of  ethane.     Used  as  local  anesthetic. 

ETHYL  lODID,  iodoethane,  C2H5I,  is  formed  when 
a  mixture  of  strong  hydriodic  acid  and  alcohol  is 
heated;  or  1)\-  adding  to  a  mixture  of  red  phosphorus 
and  alcohol,  iodin,  little  by  little,  and  then  distilling 
on  a  water -bath.      I""th\l  iodid  is  a  highl\-  refractive. 


KTHAXE    I)KRI\"ATIVKS.  257 

very  heavy  liquid,  having  an  ethereal  odor,  boiling  at 
72°,  with  a  specific  gravity  of  1.94  (14°),  and  similar 
in  its  properties  to  ethvl  chlorid  and  iodid. 
'  CH 

ETHYL    BROMID,    |  ,     or   bromethane,    is 

CH.,Br 
formed  when  ethane  is  heated  with  strong  h\  dro- 
bromic  acid,  or  it  can  be  produced  by  distilling  a 
mixture  of  sulfuric  acid,  alcohol  and  potassium 
hromid.  The  distillate  is  washed  with  alkalin  car- 
bonate and  redistilled  from  calcium  chlorid. 

It  is  a  colorless,  limpid  liquid,  with  a  chloroformic 
odor  and  a  burning  taste,  boiling  at  38°,  and  re- 
sembles chlorethane  in  its  behavior  with  alcoholic 
jjotash. 

Other  Mouolhilogen  Derivatives. — The  more  im- 
portant are  propyl  bromid,  C3H-Br;  but}l  iodid, 
C^Hgl;  propyl  iodid  has  two  isomers — nornuil  ])ro])yl 
iodid,  CH3  — CHI  — CH3,  boiling  at  102°,  and  iso- 

CH  \ 

propvl  iodid,  ^'^•■'^CHI,  boiling  at  89.5°.     Thco- 
LH3/ 

retically,  there  are  four  monohalogen  derivatives  of 

butane,   of  which   two  are  produced  from  normal 

Initane: 

CH3  —  CH,  —  CH3  — CH.X  and  CH3  —  CH,  — 

CHX  —  CH3. 

while  the  other  two  are  produced  from  isohulanc: 

CH3.  CH3 

VH—CH^X  and  VX-CHj 

CH3/  CH3/ 

Tertiary   butyl   iodid,    (CH3)3CI,   is   prepared   l)y 

treating  isobutyl  alcohol  with  sulfuric  acid  and  dis- 


258  PHARMACEUTIC    CHEMISTRY. 

solving  the  so-produced  isohutylene  in  concentrated 
hydriodic  acid;  thus: 
CH3  CH3^ 

>CH— CH3OH  = 
CU/  CH3/ 

CH3  CH3, 

■  )C=CH,  +  HI=       ■  )CI-CH3 
CH3/  CH3/ 

Another  method  is  b_\-  healing  triniethxlcarhinol  with 
HI;   thus: 

(CH3),,C  — OH  +  HI  =  (CH3)3CI  +  H^O. 

SUMMARY    OF    THE    HALOGEN    DERIVATIVES 
OF   THE    HYDROCARBONS. 

The  inorganic  compounds  of  a  metal  with  a 
hydroxyl  group  are  called  bases  and  resemble  each 
other  closely,  owing  to  their  common  constituent — 
the  OH  group.  Alcohols,  on  the  other  hand,  are 
organic  compounds,  although,  like  the  inorganic 
bases,  they  possess  the  OH  group  and,  like  the  latter, 
combine  with  acids  to  form  water. 

Inorganic  example: 

NaOH  +  HI  =  NaT  +  H,0 

sodium  hydroxid  sodium  iodid 

Organic  example: 

C2H5OH  +  HI  =  C,,H,I  +  H.,0 

ethyl  hydroxid  ethyl  iodid 

The  products  so  formed  are  comparable  with  the 
salts  of  inorganic  chemistry  and  are  commonly 
known  as  "compound  ethers"  or  cslrrs.     As  bases 

(an  lose  water,  formiiii:  ;iiih\  (bids  or  oxids,  so  also 


ALKYL    HALIDS.  259 

can  the  alcohols.  Thus,  by  abstracting  one  molecule 
of  water  jrom  two  molecules  oj  an  alcohol,  "ethers" 
are  formed.  If  two  alcohols  are  employed,  "mixed 
ethers"  are  formed.  If  an  alcohol  is  treated  with  a 
halogen  acid,  alkyl  halids  are  formed  which  have 
been  called  "halid  ethers."  Thus,  ethyl  chlorid, 
CH3CI;  ethyl  bromid,  CjHjBr;  propyl  iodid,  C3H7I, 
have  been  termed  halid  ethers. 

Preparation. — All  the  alkyl  halids  may  be  pre- 
pared by  a  similar  reaction  (Gay-Lussac,  1835); 
that  is,  by  acting  with  a  phosphorous  halid  on  a 
corresponding  alcohol,  which  yields  the  correspond- 
ing alkyl  halid  and  phosphorous  acid;  thus: 
3CH3CH2OH  +  PBrg  =  3CH3.CH2Br  +  H3PO3. 

Properties. — Like  the  inorganic  halids,  some  of 
the  alkyl  halids  slowly  precipitate  silver  nitrate  solu- 
tion; some,  however,  do  not  react  with  it  at  all.  The 
alkyl  halids  can  be  converted  into  one  another. 
For  example,  if  ethyl  chlorid  is  heated  with  potassium 
iodid,  ethyl  iodid  can  be  produced. 


CHAPTER  XXIV. 

THE     HYDROXIDS     OF     THE     HYDROCARBON 
RADICALS,  OR  ALCOHOLS. 

Among  the  several  classes  of  the  oxygen  derivatives 
of  the  hydrocarbons  are  the  alcohols,  ethers,  aldehyds 
and  the  acids.  These  may  be  said  to  be  the  most 
important  classes  and  all  the  others  to  be  derivatives 
of  these. 

Alcohols  are  formed  when  one  or  more  h\dn)gen 
atoms  of  a  hydrocarbon  is  replaced  by  the  corre- 
sponding number  of  hydroxyl  ( — OH)  grou{)s.  .Alco- 
hols are  classified  in  two  ways:  (a)  According  to  the 
number  of  hvdroxvl  groups  they  contain;  thus, 
alcohols  containing  one  hydroxyl  group  arc  called 
monatomjc  or  monacid;  those  containing  two  hydroxyl 
groups  are  called  diatomic  or  diacid;  those  containing 
three  hydroxyl  groups  are  called  triatomic  or  triacid, 
etc.  Usually,  alcohols  containing  more  than  two 
hydroxyl  groups  are  termed  polyatomic  or  polybasic 
alcohols.  (6)  According  to  their  structure;  thus, 
when  the  hydroxyl  is  linked  to  a  carbon  atom  which 
is  combined  with  only  one  other  carbon  atom,  the 
alcoliol  is  known  as  a  prim.iry  alcohol,  and  contains 
the  univalent  primary  alcohol  group  ■ — C'H.^OH. 

Primnry  alcohols  when  oxidized  yield  aldchyd 
(lud  an  acid.  When  the  hydroxyl  is  linked  to  a  car- 
bon atom  which  is  united  with  two  other  cari)on 
260 


O 

X 

o 
u 

X 

+ 

c 

Methyl  Alcohol 

Ethyl 

Propyl 

Butyl 

Pentyl  (Amvl)  Alcohol 

Hexyl  Alcohol 

Heptyl       " 

Octvl 

Cetyl 

Ceryl 

Myricyl     " 

U 

^^^^xxx 
^xxxxx^xxj%%% 

CJ  U  U'U  U  U  CJ  U  CJ  u  0 

CO 

+ 

c 

Methyl 

Ethvl 

Propyl 

Butyl 

Pentvl  (Amyl) 

Hexyl 

Heptyl 

Octyl 

Cetyl 

Ceryl 

Myricyl 

< 

M  ^.  ^,  ^  ::;  s  -s 

£ffi  ffi  ffi  m  m  K  E  %  %  \ 

U  U  U  U  U  CJ  U  CJ  CJ  u  u' 

O 
P3 

u 
o 

Pi 
Q 
>^ 
X 

+ 

W 
c 
U 

Methane 

Ethane 

Propane 

Butane 

Pentane 

Hexane 

Heptane 

Octane 

Hexadecane 

Hexacosane 

Triacontane 

CJ  CJ  tJ"CJ  CJ  U  U  U  U  CJ  CJ 

262  PHARMACEUTIC    CHEMISTRY. 

atoms,  the  alcohol  is  known  as  a  secondary  alcohol, 
and  contains  the  divalent  secondary  alcohol  group 
=  CH()H. 

Secondary  alcohols  when  oxidized  yield  ketones 
and  acids.  When  the  hydroxyl  is  linked  to  a  carbon 
atom  united  with  three  other  carbon  atoms,  the  alco- 
hol is  known  as  a  tertiary  alcohol  containing  the 
trivalent  tertiary  alcohol  group  =COH. 

Tertiary  alcohols  when  oxidized  yield  compounds 
containing  fewer  carbon  atoms. 

Preparation  of  the  Alcohols. — Alcohols  may  be 
formed  in  several  ways:  (i)  By  the  action  of  moist 
silver  oxid  upon  the  alkyl  halids;  thus: 

(a)  CH3I    +  AgOH  =     CH3OH      +  Agl 

methyl  alcohol 

(b)  C2H5I  +  AgOH  =     C3H,QH  +  Agl 

ethyl  alcohol 

(c)  C3H,I  +  AgOH  =     CgH.OH    +  Agl 

propyl  alcohol 

(2)  By  the  saponitication  of  the  esters.  The  decom- 
position of  esters  by  boiling  with  alkali  hydroxids  is 
usually  spoken  of  as  "saponification  "  with  reference 
to  its  similarity  to  the  decomposition  of  fats;  thus: 

CHaC^H^Oa   +    KOH  =     CH3OH    +  KC7H,03 

methyl  salicylate  methyl  alcohol 

(3)  By  treating  primary  amins  with  nitrous  acid; 
thus: 

NH2CH3  +  NO.OH  =  CH3OH  -t-  K,  +  H,() 

(4)  By  the  fermentation  of  fruit  juices  containing 
sugars  or  other  carbohydrates: 

QH,20„  +  ferment  =  2C2H5OH  +  2CO, 

sugar  a'cohol 


PROPERTIES    OF    THE    ALCOHOLS.  263 

The  production  of  alcohol  by  the  fourth  method 
will  be  fully  discussed  under  Ethyl  Alcohol. 

General  Properties  oj  Alcohols. — The  alcohols  are 
colorless,  neutral  substances,  among  which  those  con- 
taining but  few  carbon  atoms  are  liquids,  while  the 
higher  members  are  solids.  The  lower  members 
have  also  a  distinctive  odor,  a  burning  taste  and  arc 
soluble  in  water.  These  three  characteristics — taste, 
smell  and  solubility — diminish  with  the  increase  in 
molecular  weight.  Thus,  the  first  three  members 
are  readily  miscible  with  water — butyl  alcohol  dis- 
solves in  13  parts,  amyl  alcohol  in  40  parts,  and  so 
on.  The  proportion  of  oxygen  present  seems 
to  influence  its  solubility.  Thus,  cetyl  alcohol, 
CjgHgjOH,  which  can  be  prepared  from  sper- 
maceti, is  a  water-insoluble  solid,  very  similar  to 
paraffin  wa.x. 

Chemical  Properties. — The  structure  of  alcohols  is 
shown  by  several  reactions: 

(i)  When  alcohols  are  treated  with  alkali  metals, 
hydrogen  is  liberated  and  a  compound  of  the  hydro- 
carbon and  the  metal  is  formed.  Thus,  if  methyl 
alcohol  is  treated  with  metallic  sodium,  the  metal  is 
dissolved,  and  upon  evaporation  a  white,  hygroscopic 
solid  is  obtained,  known  as  sodium  methylate 
(methoxid),  CHgONa.  When  ethyl  alcohol  is 
treated  in  the  same  manner,  a  similar  compound  is 
obtained,  known  as  sodium  ethylate  (ethoxid)  or, 
more  commonly,  sodium  alcoholate,  QH^ONa. 
In  view  of  the  fact  that,  immaterial  to  the  quantity  of 
the  metal  employed,  onlv  one  atom  of  hydrogen  is 


264  I'lIARMACKUTlC-    CHEMISTRY. 

replaced  by  it,  it  indicates  strongly  that  only   thi- 

hydrogen  of  the  hydroxyl  group  is  rejilaced  1)\-  the 

sodium,  and  thus  proves  the  structure  of  the  alcohols: 

rH,()H  +  Na  =  CH.ONa  +  H. 

(2)  Alcohols  combine  with  acids,  neutralizing 
them  and  forming  water,  in  which  reaction  they  are 
distinctly  suggestive  of  the  behavior  of  the  metallic 
hydroxids;  thus: 

2CH3OH  +  H.SO,  =  (CH3),S(),  +  2B.,(). 

(3)  When  treated  with  phosphorus  jx^ntachlorid 
alcohols  form  alkyl  chlorids,  hydrochloric  and 
l)hosphoric  acids.  An  examination  of  the  following 
reaction  will  show  that  one  chlorin  atom  replaces  the 
hydroxyl  group  in  the  alcohol,  which  is  very  similar 
to  the  action  of  the  same  reagent  upon  water;  thus: 

4CH3OH  +  PCI5  =  4CH.,n  +  HCl  +  PO(OH)3, 
corresponding  to 

4H2O  +  PCI5  =  5HCI  +  PO(OH)3. 

A  characteristic  property  of  all  the  alcohols  is  their 
tendency  to  form  neutral  compounds  willi  the  acids. 
These  neutral,  salt-like  bodies  are  called  "ethers"  or 
"esters";  and  when  oxidized,  the  alcohols  form  acids 
containing  two  hydrogen  atoms  less  and  one  oxygen 
more  than  the  corresponding  alcohol. 

METHYL  ALCOHOL,  carl)inol,  wood  alcohol, 
wood  naphtha,  wood  spirit,  methyl  hydroxid, 
CH3OH. 

Properties. — Pure  methyl  alcohol  is  a  colorless 
liquid,  with  odor  and  taste  similar  to  ethyl  alcohol. 
It  boils  at  66.7°  and  has  a  specific  gravity  of  o.S. 
It   closelv   resembles  ordinar\-   alcohol    in   all   of   its 


DISTILLATION    OF    WOOD.  265 

properties  and  is  used  in  its  stead  as  a  solvent  for 
fats,  oils,  resins,  etc.  It  burns  with  a  nonluminous 
flame;  taken  internally,  it  intoxicates,  and  in  concen- 
trated form  it  is  highly  poisonous.  The  crude  wood 
alcohol  has  a  disagreeable  odor,  reminding  one  of 
acetone.  The  purified  varieties  are  marketed  under 
such  fanciful  names  as  "Eagle  Spirits,"  "Colonial 
Spirits,"  "Columbian  Spirits,"  etc.  In  Great  Britain 
a  tax-free,  methylated  spirit  is  employed  in  the  arts; 
it  is  a  mixture  of  lo  parts  of  crude  methyl  alcohol 
with  go  parts  of  common  alcohol. 

Preparation. — Methyl  alcohol  (from  meth,  wine, 
and  ule,  wood)  is  obtained  by  the  destructive  dis- 
tillation of  wood.      (Boyle,  1661.) 

When  wood  is  subjected  to  destructive  distillation 
without  access  of  air,  it  yields  inflammable  gases,  an 
aqueous,  strongly  acid  distillate,  some  tar,  and  the 
residue  is  wood  charcoal.  The  operation  is  carried 
out  in  large  iron  retorts,  and  the  products  may  be 
summarized  as  follows: 

Gases,  25%.  /  Carbon    raonoxid,    dioxid,    methane < 

Noncondensable.      \      acetylene,   ethylene  and   propylene. 
y  gy        [  Acetone,     furfurol,     methyl    alcohol, 

^iPOi'S    5°/o-  .    I       methylamin     and    acetic,     formic, 
butyric,     crotonic,      capronic     and 


Condensable  acid 


"^"^   ■  [      propionic  acids. 


Tarry  liquid, 
10%. 


f  Creasote,  toluol,  xylol,  cumol,  methol, 
creasol,  phlorol,  naphthalin,  pyrene, 


'^'  [      chrysene  and  paraffin. 

Residue,  15%.  Charcoal  and  inorganic  salts. 

The  aqueous  distillate  contains  methyl  alcohol 
mixed  with  acetic  acid,  acetone  and  methyl  acetate. 
This  mixture  is  known  as  pyoligneoiis  arid  and  sepa- 


266  PHARMACEUTIC    CHEMISTRY. 

rates  from  the  tarry  liquid  on  standing,  when  it  is 
decanted.  It  is  next  neutrahzed  with  lime,  whereby 
the  acetic  acid  is  converted  into  lime  acetate.  This 
mi.xture  is  then  subjected  to  distillation.  The 
volatile  methyl  alcohol  and  acetone,  together  with 
water,  pass  into  the  receiver  and  form  the  crude 
wood  spirit.  This  is  further  purified  by  fractional 
distillation  over  quicklime,  which  separates  the 
greater  part  of  the  acetone  which  has  a  lower  boiling- 
point  (56°).  Lately,  wood  alcohol  has  also  been 
produced  by  subjecting  the  by-products  of  the  beet- 
sugar  industry  to  destructive  distillation.  The 
molasses  is  fermented  and  the  ethyl  alcohol  is 
removed  by  distillation.  The  solid  residue  is  then 
dried  and  distilled  like  wood  (see  description  in 
previous  paragraph). 

ETHYL  ALCOHOL,  ethyl  hydroxid,  "grain  alcohol" 
or  comm(m  alcohol  (alcohol  U.  S.  P.),  C^HjOH. 
Ethyl  alcohol  is  obtained  by  the  fermentation  of 
certain  carbohydrates,  most  i)articularly  glucose  with 
yeast  (vinous  fermentation,  also  called  alcoholic 
fermentation).  It  has  been  shown  that  fermentation 
may  be  caused  by  the  presence  of  small  organisms, 
either  of  vegetable  or  animal  origin,  known  as  fer- 
ments. There  are  several  kinds  of  ferments.  The 
one  causing  alcoholic  fermentation  is  zymase,  a 
vegetable  ferment  contained  in  ordinary  yeast. 
These  ferments  are  sometimes  called  enzyms  and  are 
divided  into  organized  and  nonorganized  ferments. 
These  include  i)cpsase  (pepsin),  the  enzym  of  gastric 
juice;  trvpsasc  (tryi)sin).  the  cn/.yni  of  the  pancreatic 


FERMf:NTS.  267 

juice;  diastase,  found  in  malt;  amylopsase  (amvlop- 
sin),  found  in  pancreatic  secretion  and  similar  to 
diastase;  invertase,  found  in  yeast,  hydrolyzes 
sucrose  to  a  mixture  of  dextrose  and  levulose  (invert 
sugar) ;  synaptase,  from  seeds  of  the  rose  order, 
converts  amygdalin  into  benzaldehyd,  hydrocyanic 
acid  and  sugar;  myrosase  (myrosin)  exists  in  both 
the  mustard  seeds  and  hydrolyzes  the  albuminoids 
present  therein,  forming  allyl  sulfocyanid  (volatile 
oil  of  mustard) ;  papayotase,  found  in  the  juice  of 
papaw  (carica  papaya),  converts  proteids  and 
starch  into  soluble  compounds;  bromelase  (bromelin), 
found  in  the  juice  of  pineapple  fruit,  digests  pro- 
teids; rennase  (rennin),  found  in  the  gastric  juice  of 
the  fourth  stomach  of  the  calf,  coagulates  milk, 
rendering  some  caseinogens  soluble,  while  precipi- 
tating others:  these  are  respectively  known  as 
"wheys"  and  "curds";  catalase,  found  in  tobacco 
leaves,  is  an  oxidizing  enzym  which  causes  fermenta- 
tion in  fresh  tobacco  leaves,  and  is  productive  of 
the  so-called  "bouquet  of  tobacco,"  which  is  absent 
in  the  fresh  leaves. 

As  there  are  different  kinds  of  ferments,  they  also 
cause  different  kinds  of  fermentation  with  different 
products.  The  principal  kinds  of  fermentation  of 
interest  to  the  pharmaceutic  student  are  the  alcoholic 
or  vinous  fermentation,  produced  by  a  vegetable 
ferment,  zymase,  which  is  found  in  ordinary  yeast. 
The  products  of  its  action  are  alcohol  and  carbon 
dioxid. 

Acetic  Fermentation.'— T\ns  is  caused  by  a  peculiar 


268  I'lfARMACEUTIC    CHEMISTRY. 

vegetable  ferment  (mycoderma  aceti)  which  acts 
upon  alcohol,  converting  it  into  acetic  acid. 

Lactic  Fermentation. — This  is  caused  by  a  vegetable 
ferment  (bacterium  acidi  lactici)  contained  in  sour 
milk,  which  has  the  power  of  converting  sugar  into 
lactic  acid. 

The  germs  of  various  ferments  are  found  in  the 
air,  and  under  favorable  conditions  they  develop  and 
produce  their  characteristic  changes.  Such  fer- 
ments develop,  for  instance,  in  a  solution  of  grape- 
sugar,  commonly  known  as  glucose,  and  if  this  con- 
tains any  nitrogenous  body  which  is  essential  to 
their  development,  they  will  convert  the  glucose  into 
alcohol  and  carbon  dio.xid.  The  ordinary  sugar, 
which  we  call  "cane-sugar"  or  "sucrose,"  is  not 
directly  fermentable.  It  must  first  be  converted 
by  a  nitrogenous  substance,  which  is  known  as 
"invertase"  and  whichis  invariably  a  constituent  of 
yeast,  into  grape-sugar,  or  glucose,  and  fruit-sugar, 
or  fructose.  This  change  may  be  expressed  in  the 
following  reaction: 

C,,W,,0,,    +    H,0    =    CeH,30„    -h    CeH^^. 

cane-sugar  grape-sugar  fruit-sugar. 

The  above  chemical  change  or  decomposition,  in 
which  the  elements  of  water  were  added  to  effect  the 
reaction,  is  known  as  hydrolysis.  Invertase,  there- 
fore, is  a  "hydrolytic  ferment  "  or  "enzym."  Either 
of  these  two  sugars  so  produced  (fructose  and  glucose) 
are  directly  fermentable  with  yeast,  forming  the  alco- 
hol and  by-products.  It  may  be  added  that  the 
reaction  expressing  the  formation  of  alcohol  from 


ALCOHOL    MANUFACTURE.  269 

glucose  is  not  as  sim])le  as  it  may  appear  at  first 
sight;  for,  in  addition  to  the  alcohol  and  carbon 
dioxid  produced,  two  amyl  alcohols  are  produced 
which,  together,  constitute  the  "fusel  oil";  propyl 
and  isobutyl  alcohol,  a  little  succinic  acid  and 
about  2.5%  of  glycerin  are  formed  at  the  same  time. 
Manufacture  of  Alcohol  and  Beverages. — The  grain, 
which  may  be  either  maize,  rye,  rice,  oats,  potatoes  or 
other  starch-rich  fruits  (molasses  is  frequently 
used)  is  ground  to  a  meal  and  macerated  in  water  at 
a  temperature  between  85  and  88°  C.  This  process 
is  called  "mashing,"  in  which  the  starch  is  changed 
into  soluble  form,  such  as  dextrose  or  maltose.  This, 
upon  the  addition  of  malted  barley  or  rye,  at  a  tem- 
perature of  60°  C,  is  converted  by  the  action  of 
diastase  into  glucose.  This  liquid  is  cooled  to 
about  18  °C.,  yeast  is  added  and  the  glucose  is  broken 
up  into  carbon  dioxid,  which  is  evolved  and  escapes, 
and  alcohol,  which  remains  in  the  liquid.  Other 
products  formed  at  the  same  time  are,  as  said  before, 
propenyl,  propyl,  isobutyl  and  amyl  alcohols,  to- 
gether with  succinic  acid.  These  latter  are  less 
volatile;  that  is,  have  a  higher  boiling-point  than  the 
ordinary  alcohol,  which  is  obtained  by  fractional 
distillation.  This  distillation  is  best  conducted  in  a 
"columnar  still,"  best  known  as  "Coffey's  still." 
The  ordinary  alcohol,  besides  the  admixture  of  the 
above  alcohols,  also  contains  much  water,  from  which 
it  may  be  separated  b}-  fractional  distillation.  It, 
boiling  at  78°  C,  is  separated  from  the  water  readily, 
while  the  fusel  oil  is  separated  partly  by  distillation. 


270  PHARMACEUTIC    CHEMISTRY. 

and  the  last  traces  of  it  by  filtering  the  alcohol 
through  animal  charcoal.  Animal  charcoal  has  the 
property  of  absorbing  foreign  odors  and  the  process 
is,  therefore,  known  as  "deodorization."  The 
water  cannot,  however,  be  completely  removed  b\- 
redistillation,  though  a  product  containing  about 
96%  of  alcohol  may  be  obtained  by  that  process. 

Absolute  alcohol  is  prepared  from  ordinary  alcohol 
by  removing  the  water  from  it  by  means  of  some 
dehydrating  agent,  such  as  quicklime  or  anhydrous 
copper  sulfate.  Thus,  by  repeated  treatment  with 
lime,  the  water  can  be  reduced  to  0.5%,  and  this 
small  quantity  can  be  further  removed  by  treatment 
with  metallic  sodium.  The  commercial  varieties  of 
absolute  alcohol  contain  about  99%.  The  Pharma- 
copoeia recognizes  three  forms  of  alcohol — the  ordi- 
nary alcohol,  containing  92.3%  by  weight  or  95%  by 
volume  of  absolute  alcohol;  the  absolute  alcohol 
(alcohol  absolutum  U.  S.  P.),  which  should  contain 
not  more  than  1%  by  weight  of  water;  and  the  diluted 
alcohol  (alcohol  dilutum  U.  S.  P.),  containing  41% 
by  weight  or  49%  by  volume  of  absolute  ethyl  alcohol. 

Tlie  requisites  jor   successjul   jcnticntation    are 

(1)  Glucose,  loo.o  parts 

(2)  Albuminoids,  i.o  parts 

(3)  Mineral  salts.  0.5  parts 

(4)  Yeast,  0-5  parts 

102.0  j)arts 

(5)  Air,  at  the  outset. 

(6)  A  temperature  between  5  and  30°  C 


ALCOHOLIC    BEVERAGES.  27  I 

And  the  products  of  fermentation  may  be  tal)ulated 
as  follows: 

(i)  Ethyl  alcohol,  48.5  parts 

(2)  Carbon  dioxid,  46.5  parts 

(3)  Glycerin,  3.6  parts 

(4)  Succinic  acid,  0.7  parts 

(5)  Fusel  oil  and  extractives,  0.7  parts 

(6)  Yeast,  increased  to  2.0  parts 

102.0  parts 

(7)  Traces  of  organic  esters  which  give  the  fer- 
mented product  its  "bouquet." 

Beer  Manujadure. — Barley  is  moistened  with 
warm  water,  strewn  upon  warm  floors  and  allowed 
to  germinate  (sprout) .  During  this  process  a  ferment, 
called  diastase,  is  developed  which  converts  part  of 
the  starch  into  sugar.  The  barley  is  now  dried 
quickly  to  prevent  further  growth,  and  it  constitutes 
the  so-called  "  malt."  This  malt  is  ground  to  a  meal 
and  placed  in  water  at  about  the  temperature  of 
76°  C,  to  allow  the  diastase  to  act  on  the  unaltered 
starch.  The  liquid  is  then  strained  and  is  now  called 
"  wort,"  to  which  hops  are  added  to  give  it  the  bitter 
taste  and  flavor.  Yeast  is  now  mixed  and  the  fer- 
mentation is  allowed  to  proceed  to  a  certain  point, 
but  never  to  a  completion.  The  yeast  is  then  sepa- 
rated and  the  beer  is  drawn  off  into  casks  and 
subjected  to  high  chilling  "vatting,"  in  which 
process  the  yeast  which  remains  floating,  deposits 
and  becomes  dormant.  The  best  process  for  fer- 
mentation is  dependent  upon   the   correct   mainte- 


272  I'll  AKMACKITIC    (.11 KMIS  TRN  . 

nance  of  the  tem])eratuix'.  Thus,  in  the  I'niled 
States,  a  tempeniture  of  between  15  and  16"  C.  is 
maintained,  and  the  same  may  be  said  of  Great 
Tiritain,  while  in  France  and  Germany  the  tempera- 
ture is  not  j)ermitted  to  exceed  12°  C.  Good  beer 
should  not  contain  alcohol  in  excess  of  3%,  and 
bock  beer  in  excess  of  4' , . 

Lager. — This  is  a  beer  brewed  at  a  temperature 
between  5  and  10°  C.  This  low  temperature  keejjs 
the  yeast  at  the  bottom  and  hence  the  fermentation  is 
much  more  com])lete.  Lager  contains  between  5 
and  7%  of  alcohol. 

Ale. — In  the  manufacture  of  ale  the  temperature 
is  maintained  comparatively  high — between  15  and 
30°  C.  The  bubbles  of  carbon  dioxid  rise  and  carry 
the  yeast  to  the  surface,  forming  there  a  thick  stum. 
This  mechanically  checks  the  Oxidation  and  hence 
the  fermentation.  After  the  ale  has  been  drawn  ott 
into  the  casks  the  fermentation  starts  up  again  and 
continues  for  some  lime. 

Whisky  Maniijacture. — Whisky  is  usually  made 
from  corn,  but  frequently  from  r\e,  wheat,  potatoes 
or  other  starch-bearing  vegetables".  The  grain  is 
ground  to  a  meal  and  mixed  with  water  and' a  very 
little  mall.  This  latter  furnishes  the  diastase  nec- 
es.sary  to  (omerl  the  starch  into  sugar.  This  mix- 
ture, called  "mash,"'  is  kept  at  a  warm  temperature 
until  all  the  starch  has  been  acted  upon.  The 
liquid  is  then  drawn  off  and  mi.\e<l  with  the  yeast. 
It  is  allowed  to  ferment  as  nuu  h  as  possible,  for  it  is 
desirable  to  uet  all  the  ah ohol  that  can  be  obtained. 


RECTIFICATION.  273 

It  is  next  distilled  and  the  distillate  constitutes  the 
raw  whisky,  commonly  called  "high  wine." 
High  wine  contains  alcohol  and  water  in  nearly 
equal  proportions.  Its  strength  is  designated  by  the 
number  of  "proof  degrees"  by  the  United  States 
Internal  Revenue  Bureau:  two  proof  degrees  being 
equal  to  i%  by  volume  of  absolute  alcohol.  The 
whisky  employed  for  medicinal  purposes  (spiritus 
frumenti  U.  S.  P.)  should  correspond  to  an  alcoholic 
strength  of  44  to  55%  by  volume  and  stand  in  barrels 
not  less  than  four  years.  During  this  standing  in 
barrels,  whisky  is  mellowed,  developing  a  number 
of  esters  which  increase  and  enhance  its  bouquet, 
and  such  mellowed  whisky  is  called  "old  whisky." 

Rectification  is  the  purification  of  alcohol  and 
strong  alcoholic  liquors  by  the  removal  of  water  and 
fusel  oils,  chiefly  by  distillation.  Ethyl  alcohol 
volatilizes  at  a  lower  temperature  than  these,  and  by 
carefully  regulating  the  temperature  at.  a  certain 
point,  these  by-products  will  be  left  beliind  in  the 
body  of  the  still. 

Wines. — \\'ines  may  I:>c  said  to  be  the  fermented 
juice  of  grapes.  When  grapes  are  expressed  and 
with  their  skins  permitted  to  stand  at  a  temperature 
not  exceeding  30°  C,  they  ferment,  giving  rise  to  red 
wines.  If  the  juice,  however,  has  been  strained  off 
from  the  skins  before  the  fermentation  sets  in,  white 
wines  will  be  the  product.  If  fermentation  is  per- 
mitted to  proceed  to  almost  completion,  "dry"  wines 
are  obtained.  These  are  subjected  to  distillation  and 
all  but  al)out  •]^\  of  their  alcohol  is  removed  by  dis- 
r8 


274  PHARMACEUTIC    CHKMISTRV. 

tillation.  The  alcohol  so  removed  possesses  a  flavor 
and  a  bouquet  peculiar  to  itself,  and  when  obtained 
from  champagne  grapes  is  termed  "cognac";  but 
when  obtained  from  the  ordinary  grape  it  is  termed 
"brandy."  Brandy  is,  therefore,  the  liquor  obtained 
by  distilling  wine  (spiritus  vlni  gallici  U.S.  P.),  con- 
taining from  46  to  55%  of  alcohol  by  volume,  and 
at  least  four  y^ars  o'.d.  When  the  fermentation  is  not 
permitted  to  continue  to  completion,  sweeter  wines  are 
produced.  These  sweeter  wines,  of  which  port, 
angelica  and  sherry  are  the  types,  contain  upward 
of  18%  of  alcohol,  whereas  the  dry  wines,  such  as 
claret  or  hock,  contain  7  and  9%,  respectively. 

Rum  is  made  from  molasses  by  fermentation  and 
distillation. 

Gin  is  made  by  macerating  crushed  juniper  ber- 
ries in  60%  alcohol  and  then  subjecting  to  distillation. 

Other  beverages,  such  as  porter,  which  may  be 
said  to  be  "evaporated  beer,"  we  shall  not  treat  of. 

DECAY. — It  is  well  known  that  many  moist  organic 
substances  when  exposed  to  the  air  undergo  a  slow 
process  of  oxidation,  and  so  are  gradually  destroyed 
without  sensible  rise  of  temperature.-  This  process 
of  slow  combustion  or  oxidation  differs  from  fer- 
mentation, and  is  called  decay. 

Properties  oj  Ethyl  Alcohol.— VA\^\\  alcohol  is  a 
colorless,  transparent,  mobile  liquid  of  a  character- 
istic agreeable  odor  and  burning  taste.  It  boils 
at  78°  C.  and  has  a  specific  gravity  of  0.809  (25°  C). 
It  is  miscible  with  water,  ether,  chloroform  and, 
with  the  exception  of  water,  it  is  the  most  generally 
employed  solvent  in  pharmacy.     It  is  one  of  the  best 


ADULTERATION    OF    ALCOHOL.  275 

solvents  for  resins,  alkaloids,  essential  oils,  camphor, 
iodin  and  many  organic  and  inorganic  compounds. 
It  does  not  dissolve  the  fixed  fats.  It  is  very  in- 
flammable. Its  most  common  impurity  is  aldehyd. 
The  presence  of  aldeh}d  is  detected  by  the  addition 
of  silver  nitrate  which  produces  discoloration;  oak 
tannin  in  presence  of  potassium  hydroxid  T.  S.  gives 
a  brownish-yellow  color.  When  25  c.c.  of-  alcohol 
are  evaporated  spontaneously,  the  barely  moist  sur- 
face of  the  dish  should  not  be  colored  red  or  brown, 
with  5  drops  of  concentrated  H2SO4  which  shows  the 
absence  of  fusel  oil  and  organic  impurities. 

Chemical  Properties  oj  Ethyl  Alcohol. — Alcohol 
may  be  detected  by  warming  it  with  a  little  iodin  and 
potassium  hydroxid,  when  crystals  of  iodoform  will 
separate  and  can  be  identified  by  their  smell  and 
crystalline  form.  With  chlorin  it  forms  chloral, 
and  with  bleaching  powder  and  water,  chloroform. 
With  strong  nitric  acid  it  evolves  ethyl  nitrate.  When 
it  is  mildly  oxidized,  it  is  converted  into  acetaldehyd; 
and  if  subjected  to  strong  oxidation,  it  is  converted 
into  acetic  acid.  With  chromium  trioxid  alcohol 
ignites  spontaneously  and  burns  to  carbon  dioxid 
and  water.  When  treated  with  sulfuric  acid,  it 
forms  ethyl  sulfuric  acid,  commonly  known  as 
"  sulfovinic  acid."  If,  however,  an  excess  of  alcohol 
is  heated  with  sulfuric  acid,  ether  is  formed  by 
the  abstraction  of  water,  the  acid  simply  acting  as 
a  dehydrating  agent. 

Adulteration  of  Ethyl  Alcohol  and  Alcoholic  Bever- 
ages.— Frequently,  for  the  purpose  of  reducing  the 
cost  of  beverages  and  more  frequently  in  reducing 


276  PHARMACEUTIC    CHEMISTRY. 

the  cost  of  remedial  agents  for  external  application, 
and  of  those  given  in  but  small  doses,  part  or  all  of 
the  ethyl  alcohol  is  substituted  by  methyl  alcohol.  In 
the  first  instance  it  is  sophistication;  in  the  second 
instance,  substitution.  To  detect  the  presence  of 
ethyl  alcohol  in  such  mixtures  the  following  method 
can  be  employed  to  advantage: 

The  alcohol  or  a  solution  of  it  is  subjected  to 
distillation  and  the  portion  distilling  between  60  and 
80°  is  collected.  A  spiral  of  copper  wire  is  heated 
to  redness  and  plunged  into  the  liquid  several  times, 
after  which  it  is  filtered.  One  drop  of  a  0.5%  aqueous 
resorcinol  solution  is  added,  and  the  mixture  is 
floated  upon  concentrated  sulfuric  acid.  A  rose- 
red  zone  at  line  of  contact  indicates  ethyl  alcohol; 
a  scanty  white  or  ])inkish  coagulum  appears  directly 
above  the  zone  and  finally  separates  and  rises  in 
purplish  flakes  (similar  reactions  are  given  by  the 
tertiary  butyl  alcohols  and  formic  acid,  l)ut  the  suc- 
cession of  colors  and  the  deportment  of  flaky  coloring 
matter  are  different). 

Nomenclature  0}  the  Alcohols. — It  is  sometimes 
desirable  to  consider  all  of  the  alcohols  as  derivatives 
of  methyl  alcohol — Carbinol.     This  greatly  facilitates 
the  naming  of  the  alcohols.     Thus: 
Carl)in()I  is  methvl  alrohol,  CH,()H 

Methyl  carbinol  is  ethyl  alcohol,  CH.CH.OH 

Ethyl  carbinol  is  propyl  alcohol,  ("JUCIIX^H 

Dimethyl  carbinol  is  isopropvl  alcohol,  CII  ;C'TI()IICH  , 

IVopvl  carbinol  is  butvl  alcohol,  (-,H,CH.,C)H 

Trimelhyl  carbinol  is  'isobuty!  alcohol,  (CII,),C()H 

Isopropyi  carbinol  is  primary  isobiityl  alcoiiol,   CH^CII.-OH 

Isomerism   amoiii^  the  Alcohols. — Tlic  possibili- 


OXIDATION    OF   ALCOHOL.  277 

ties  of  isomerism  among  the  alcohols  arc  even  greater 
than  among  the  hydrocarbons.  Thus  it  may  arise  in 
thi-ee  ways:   ((/)  by  branching  of  the  carbon  chains; 

(b)  by  changing  the  position  of  the  hydroxyl  group; 

(c)  or  through  both  of  these  simultaneously.  Thus, 
while  methyl  and  ethyl  alcohols  have  no  isomers, 
there  are  two  propyl  alcohols,  the  normal  and  the 
iso-;  four  butyl  alcohols;  eight  amyl  alcohols,  etc. 

TJie  Propyl  Alcohols. — Normal  propyl  alcohol 
has  a  boiling-point  of  97.4°  and  may  be  separated 
from  fusel  oil  by  fractional  distillation,  while  iso- 
propyl  alcohol  boils  at  82. 7°  and  is  obtained  by  acting 
on  acetone  with  sodium  amalgam.  The  following 
are  the  graphic  formulas  of  the  two  propyl  alcohols: 

CH3 

I  ■    CH3CH3 

CH,  \/ 

I  .  CHOH 

CHjOH  isopropyl  alcohol, 

normal  propyl  alcohol 

The  following  are  the  graphic  formulas  of  the  four 

butyl  alcohols: 

CHj  CH3 

I  CH3C3H  1  CH3CH3 

CH.  \/  CH.  \y 

I  CH  I  COH 

CH.  I    -  CHOH  I 

J,  CH^OH  I  CH3 

CH^OH  isobutyl  ^^3 tertiary  butyl 

normal     butyl  alcohol  secondary  butyl         alcohol 

alcohol  alcohol 

The  Eff eels  oj  Oxidation  Upon  the  Alcohols. — It  has 
been  said  that  primary  alcohols  upon  oxidation  yield 
aldehyd,  and  when  subjected  to  still  further  oxida- 


278 


PHARMACEUTIC    CHEMISTRY 


Specific 
gravity 
at  20% 

0.804 
0.789 

0.810 

0.806 
0.786 

0.815 
0.81b 

Boiling- 
point. 

00         0000         0000    0^0    0    0 

t^«          t^Ot^r^       00"COCN(Nr^N<N 
O-CO            "OOOO            r^r--,  r<-.„«0" 

s 
p2 

X 

0 

^  &  Yg^5§Yig 

u  1     yu  19     LVw  LVeSs 

VY  YY4i  T^Vf^U^ 

6 
E 

Propyl  Alcohols,  CjHgO : 

(i)  Normal, 

(2)  I so, 
Butyl  Alcohols,  C4H10O: 

( 1 )  Normal  primary, 

(2)  Normal  secondary, 

(3)  ^^0, 

(4)  Trimethylcarbinol, 
Amyl  Alcohols,  CsH.^O: 

(i)   Normal  primar>', 

(2)  /sobutylcarbinol, 

(3)  Secondary  butyirarbinol, 

(4)  Methyipropylcarbinol, 

(5)  Methyi/sopropylcarbinol, 

(6)  Diethycarbinol, 

(7)  Dimcthylethylcarbinol, 

(8)  Tertiary  butvlcarbinol, 

SECONDARY   ALCOHOL. 


279 


tion,    they    yield    acid^ 
demonstrate  this  fact: 
CH, 

I 


H- 


-c  :  H  +  o 

I    : 
o  :H 


alcohol 
CH3 


+  o 


The    following    reactions 

CH3 

H— C  +H.O 

O  

acetaldehyd 

CH, 

!    OH 

\/ 

c=o_ 

acetic  acid 


acetaldehyd 

The  secondary  alcohols  in  the  first  stage  of  oxida- 
tion also  lose  2  atoms  of  hydrogen,  but  the  resulting 
compounds  are  termed  "ketones."  Thus  secondary 
propyl  alcohol  (iso-)  upon  oxidation  yields  dimethyl 
ketone,  commonly  known  as  acetone.  Ketones 
upon  further  oxidation  split  up  into  acids  having 
fewer  carbon  atoms,  carbon  dioxid  and  water.  The 
following  reactions  illustrate  this: 
CH3CH3 


C  H.     O  H  + 


isoprophyl 
alcohol. 


CH, 

I 
C  =0  +  H,0 

I 
CH., 


CH, 


CH, 


dimethyl  ketone 
(acetone) 


C^ 

I 

CH, 


:0      +     2O, 


dimethyl 
ketone 


+  CO.,  +  H,0 


OH 

acetic  acid 


28o  IMIAKMAC  KITIC    CUKMISTRY. 

When  tertiary  alcohols  are  oxidized  they  form  ke- 
tones or  acids  with  fewer  carbon  atoms  than  the 
original  alcohol  containetl.  Thus  the  tertiar\- 
butyl  alcohol  containing  4  carbon  atoms  splits  uj) 
into  dimethyl  ketone  (containing  three  carbons), 
carbon  dioxid  and  water,  as  the  following  reaction 
illustrates: 

CH3  CH^ 

I  ■  I 

H,C-C-(3H  +  2  0.  =  C  =  0  +  C02  +  2H.,0 

I  "      i  '      ■ 

CH3  CH3 

The  nature  of  the  alc(,)hols  may  be  determined  by 
still  another  process  than  the  oxidation  method. 
The  oxidation  method  is  somewhat  tedious  and  a 
"color-test  diagnosis"  has  been  recommended. 
(Victor  Meyer. ) 

The  alcohol  is  converted  into  alkyl  halid  by  treat- 
ment with  red  phosphorus  and  iodin;  the  iodid  is 
dried  with  calcium  chlorid  and  then  distilled  with 
silver  nitrite.  A  nitroparaffin  is  obtained  which  is 
mixed  with  potassium  nitrite  and  dilute  potassium 
hydroxid.  Dilute  sulfuric  acid  is  next"  added  drop 
by  drop.  If  this  plroduces  a  red  color  it  indicates  a 
prinnry  alcohol;  a  blue  color  points  to  ^secondary; 
while  no  coloration  indicates  a  tertiary  alcohol.  (This 
test  is  sometimes  called  "the  red,  blue  and  white 
test.") 

AMYL  ALCOHOL,  pentyl  alcohol,  C.,H„OH. 
This  alcohol  derives  its  name  Irora  amylum,  starch. 
Two  of  its  eight  isomerids  constitute  the  so-called 


AMYL    NITRITE.  28 1 

fusel  oil.  Fusel  oil  is  a  mixture  of  the  secondary 
butyl  carbinol  and  isobutyl  carbinol,  has  a  character- 
istic, unpleasant  odor  and  is  not  miscible  with  water, 
but  floats  upon  it  like  an  oil,  from  which  it  derives 
its  name  "  fusel  oil."  Fusel  oil  is  obtained  from  high 
wine,  but  the  glucose  obtained  from  potato  starch 
yields  a  considerably  greater  amount  of  it,  and  hence 
amy]  alcohol  is  sometimes  known  as  "potato  oil." 

Properties. — Commercial  amyl  alcohol  is  an  oily, 
yellowish  licpiid  which,  '  when  oxidized,  yields 
valeric  acid. 

AMYL  NITRITE,  CsH^jNOa,  is  prepared  by  a 
process  similar  to  that  employed  in  the  making  of 
ethyl  nitrite;  that  is,  by  distilling  a  mixture  of  the 
alcohol,  sodium  nitrite  and  sulfuric  acid.  Amyl 
nitrite  is  a  highly  aromatic  substance,  has  a  low 
boiling-point  and  should  consist  of  at  least  80%  of 
isoamyl  nitrite  (amylis  nitris  U.  S.  P.) 

AMYL  ACETATE,  CjHn— CoHgO,.  This  ester  is 
prepared  bv  distilling  a  mixture  of  amyl  alcohol, 
sodium  acetate  and  sulfuric  acid.  It  constitutes  the 
jargonelle  pear  essence.  Mixed  with  methyl  alcohol 
and  benzin,  it  constitutes  the  so-called  "banana  oil" 
of  the  painters,  used  to  suspend  aluminum  and  gold 
l)ronzes  for  painting. 

AMYLENE  HYDRATE,  ethyl  dimethyl  carbinol,  is 
used  as  a   hypnotic  (CH3)3C.  CHjOH.     On  oxida- 
tion it  yields  only  acetic  acid: 
CH3.         .OH 

cn/  ^CH,  — CH3 

amylene  hydrate 


CHAPTKR    XXV. 
DIATOMIC  ALCOHOLS  OR  GLYCOLS. 

The  alcohols  of  the  olefins  or  the  ethylene  series 
are  all  diatomic  or  diacid.  They  contain  two 
hydroxyl  groups  in  the  molecule,  they  are  heavy  and 
viscid,  reminding  one  of  glycerin,  and  hence  the 
name  "glycols"  is  applied  to  the  group.  The 
glycols  are  not  very  interesting  to  the  pharmacist. 

Properties. — The  glycols  can  be  easily  prepared 
from  the  dihalogen  derivatives  of  the  olefins  by  the 
action  of  water  and  a  metallic  oxid  in  much  the  same 
way  as  the  monatomic  alcohols  are  obtained  by 
treating  the  alkyl  halids  with  an  alkali;  thus: 
CjH.CI,  +  2KOH  =  r.,H,(OH),  +  2KCI. 

ethylene  glycol 

The    glycols    are    colorless,    viscid   liquids   with    a 

high  boiling-point.     Thus,  ethylene  glycol  boils  at 

195°  C.     They  are  all  very  soluble  in  water.     The 

glycols  exhibit  all  the  properties  of  the  alcohols,  but 

doubly.     Thus,  ethylene  glycol  contains  two  primary 

alcohol  groups,  and.  by  successive  oxidation  of  these 

groups  to  aldehyd  and  carboxyl  groups,  the  following 

series  of  products  should  be  derivable.     However, 

only  the  second,  third  and  fifth  have  been  obtained 

from  glycol  by  oxidation. 

(i)  (2)  (3)  (4)  (5) 

CH.OH  CH.OH         Clio  CHO  COOH 

CHO    coon   CHO   coon   cooh 

glycoilic  glycollic  glyo.xal         glyoxallic        oxallic  acid 

aldehyd  acid  acid 

282 


ETHYLENE    OXID.  283 

Among  the  more  interesting  compounds  of 
ethylene  glycol  the  following  may  be  mentioned: 

When  hydrochloric-acid  gas  is  passed  into  glycol, 
one  of  its  hydroxyls  is  replaced  by  the  chlorin,  form- 
ing a  chlorhydrin  and  splitting  off  water.  When, 
however,  glycols  are  treated  with  phosphorus 
pentachlorid,  both  hydroxyls  are  replaced,  and 
ethylene  chlorid  is  formed;  thus: 


(i)  CH,.OH 

1     "         +  HCl  = 
CH,.OH 

CH,.C1 
=  1     "        +H,0 
CH^.OH 

(2)  CH,.OH 

1     "          +  2PCI. 
CH..OH 

ethylene 
chlorhydrin 

CH2.CI 

=    1                  +  2POCI,   +  2HCI 

CH,.C1 

ethylene 
chlorid 

When    caustic    alkalis    act    upon    chlorhydrins, 
"ethylene  oxids  "  are  formed: 
CH2.CI  CH.. 

I  +  KOH  =1        )0    +  KCl  +  H.O 

CH2.OH  CH/ 

ethylene 
oxid 

When  ammonia  gas  acts  upon  ethylene  chlorid, 
it  replaces  the  chlorin  with  two  amido  groups  and 
forms  diamin: 

CH..C1  CH,.NH, 

I     "       +  4NH3  =  I     "  +  2NH,CI. 

CH.Cl  CH^-NH, 

ethylene 
diamin 

This  is  a  primary  diamin,  with  basic  properties  of 
the  amins. 


284  I'UARMACKUTIC    CHLIMISTRV. 

Choliii,    nciirin,    laiirin,    may    all    be    said    to    be 
derivatives  of  eth}lcne  glycol;  thus: 
CH,OH  Cl\2  CII,.NH,\ 

!    -  _  11  -.1  •  )o 

CH,N:(CH,)3.0n        CH.N:(CH,)3.Qli        CH..SOa/_ 
cholin  neurin  taurin 

ChoJin  is  found  in  the  brain  and  egg-yolk,  forming 
with  glycerol,  stearic  and  i)hosphoric  acids  a  com- 
plex compound — lecithin  {C^^  Hgg  N3O9P).  Neu- 
riii  is  a  product  of  the  putrefaction  of  albumin,  and 
classed  among  the  ptomaines.  2\iurin  is  a  constit- 
uent of  bile. 

The  second  of  the  oletinic  alcohols  is  a/Zy  alcohol 
CH2  =  CH  —  CH2OH.  It  is  derived  from  the 
second  member  (propylene)  of  the  olefin  hydrocar- 
bons, and  is  prepared  by  heating  isopropylene,  allyl 
iodid  (C3H5I)  with  water  at  100°.  The  isothiocy- 
anate  of  this  alcohol  constitutes  the  essentuil  oil  of 
mustard,  and  the  sultki  constitutes  oil  oj  i^arlic: 


CH,\ 
CH— N  = 
CH,/ 

S 
li 

=c 

muslai 
d  black 

CH,             H,C 

1     '\     /    "1 
CH  —  S  — H  C 

1       /     \       1 

allyl  isothiocyanate 

In  nature,  the  oil  of 
by  macerating  grouni 

CH,         -    H2C 

allyl  sulfid 

d  (essential)  is  obtained 
mustard  seeds  with  cold 

water  and  distilling  the  product  with  steam.     The 
potassium  myronate — a  glucosid  of  the  seeds — is  fer- 
mented by  myrosin,  an  enzym  present,  and  the  oil, 
glucose  and  potassium  bisulfate  are  formed;  thus: 
Q„H.„NS20,K   4-  H2O  =  C3H  =N  =  C  =  S  + 

C„H,20„   +    KHSC),.  ^"yl   isothiocyanate. 


TRIATOMIC    ALCOHOLS    OR    GLYCERINS.  285 

TRIATOMIC    ALCOHOLS    OR    GLYCERINS. 

As  the  monatomic  alcohol  CHjOH  corresponds  to 
the  inorganic  hydroxid  NaOH,  and  the  diatomic 
glycol  C2H4(OH)2  to  the  inorganic  calcium  hydroxid 
Ca(0H)2,  so  do  the  triatomic  alcohols,  as  glycerin, 
C3H5(OH)3,  correspond  to  ferric  hydroxid,  Fe(OH)3. 

GLYCERIN,  glycerol,  propenyl  alcohol,  is  a  clear, 
odorless,  colorless,  sweet  liquid,  having  the  specific 
gravity  1.246  and  a  boiling-point  of  290°.  It  cannot 
be  distilled  alone,  but  it  is  readily  distilled  with 
superheated  steam  under  reduced  pressure.  It  is 
very  hygroscopic,  neutral,  and  dissolves  in  water  and 
alcohol,  but  is  insoluble  in  chloroform,  benzol  and 
the  fixed  oils.  It  was  discovered  by  Scheele  (1779), 
who  isolated  it  while  making  lead  plaster;  and 
Chevreul  found  it  to  be  the  constituent  of  natural 
fats  and  oils.  It  can  be  prepared  from  fats  by 
saponification,  by  decomposing  these  with  caustic 
alkalis;  also  by  passing  superheated  steam  through 
a  fat.  This  last  method  is  the  one  most  commonly 
used  in  the  manufacture  of  glycerin.  Glycerin  does 
not  freeze  until  about  — 17  °,  and  for  that  reason  it  is 
valued  in  gas  meters  and  automobiles  which  must  be 
exposed  to  low  temperatures.  Large  quantities  of  it 
are  employed  in  the  manufacture  of  glyceryl  nitrate 
(nitroglycerin),  from  which,  in  turn,  dynamite  is 
made.  In  pharmacy  it  is  used  as  a  solvent.  Its 
graphic  formula  shows  it  to  be  composed  of  three 
alcoholic  groups,  of  which  one  is  secondary  and  two 
are  primary: 


OF   THE 

UNIVERSITY 

OF 


286  THARMACEUTIC    CHEMISTRY. 

CH2.OH 

I 

CH.OH 

I 
CH2.OH 

glycerol  =  C3H3(OH)3. 

Chemical  Properties  oj  Glycerin. — When  heated 
with  sulfuric  acid,  acrolein  is  formed,  which  is  recog- 
nized by  its  odor.  It  liberates  boric  acid  from 
borax.  With  chlorin  it  forms  mono-,  di-  or  tri- 
chlorhydrins: 

CH2CI  CHjCl  CH,C1 

CHOH     ►     CHCl >     CHCl 

I  I  I  ^ 

CH.;OH  ^H^Cl^  CHX'l 

monochlorhydrin  dichlorhydrin  trichlorhydrin 

Glycerin  should  not  reduce  Fehling's  solution, 
showing  the  absence  of  glucose  (its  frequent  adulter- 
ant). Glycerin  dissolves  coloring  matters,  tannin 
and  extractives,  and  may  be  called  an  "intermediate  " 
solvent  between  alcohol  and  water.  It  increases 
specific  gravity  of  fluid  extracts  and  tinctures,  pre- 
venting their  precij)itation. 

Structure. — The  structure  of  glycerol  has  l)een 
determined  by  several  syntheses,  of  whi\h  the 
following  one  may  be  given  as  an  example: 

CH3            CH3           CH,         CH,v 
I             —  I            _  I         -^            )CHOH— 
9M^9^      COOH      c  =  o      CH,/ 

alcohol  acetic  |  isopropyl  alcohol 

acid  CH, 


GLYCERIC    ACID.  287 

CH,       CH3  CHj.Cl       CH2.OH 

II         I         I 

CH  — .  CHCl  — .  CH.Cl  —  CH.OH 

II             I  I                   I 

CH,       CH.Cl  CH,.C1       CH,.OH 

propylene    propylene  3  chlor-          glycerol 

dichlorid  hydrin 

When  acetone  is  reduced,  isopropyl  alcohol  is 
formed  which,  when  heated  with  sulfuric  acid,  forms 
propylene.  Propylene,  in  turn,  combines  with 
chlorin,  giving  propylene  chlorid  which,  when 
treated  with  iodin  chlorid,  is  converted  into  trichlorhy- 
drin.  Trichlorhydrin,  heated  with  water  to  170°, 
yields  glycerol : 

CH2CI        HOH  CH^OH 

CHCl   +   HOH    =    CHOH     +   3HCI. 

I  I 

CHXl       HOH  CH^OH 

When  glycerol  is  reduced  with  hydrogen,  the 
secondary  group  is  attacked,  giving  rise  to  dioxy- 
acetone,  CH^OH  —  CO  —  CH^OH.  AUyl  alcohol 
(found  in  oil  of  garlic),  when  oxidized  with  potas- 
sium permanganate,  yields  glycerol.  The  trivalent 
radical  of  glycerin  is  sometimes  termed  "glyceryl." 
When  one  of  the  primary  alcohol  groups  is  oxidized, 
CH2OH 

I 
glvceric  acid— CHOH — is    formed.     Upon    further 

I 
CO.OH 

oxidation,    the    second    primary    alcohol    group    is 

affected,    and    tartronic    acid    is    formed.      W'hen 

dioxyacetone   is  treated  with  caustic  soda,  it  is  con- 


288  PHARMACEUTIC    CHEMISTRY. 

verted  into  glyceric  aldehyd,  which  condenses  with 

part  of  the  dioxyacetone,  giving  rise  to  an  artificial 

sugar    which,    chemically,    is    an    inactive   fructose 

(a-acrose),  to  which  the  name  aldol  has  been  given. 

.\ldol  may  be  synthetized  as  follows: 

CH,.OH  CH.,OH  CH,.OH      CH^OH 

i  I     '  I  I 

CH.OH      +      C  =  0      =      CH.OH       C  =  0 

i  III 

CHO  CH.OH         CH.OH        CHOH 

_^  __    "  I I 

>j;lyceric      dioxyacetone      aldol     _  C,.H,.,0 

aldehyd  "      i-      '' 

Manitj ictiD-c  of  Glycerin.— (i)  By  superheating 
stearin  with  water: 

C3H5    (C,,U,,0,),    +    3%0    =    3HQ8H35O2    + 

tristearin  stearic  acid 

C,H-  (OH) 3. 

glycerin 

(2)   As  a  by-producl  in  the  manufacture  of  soap. 
When  fats  are  boiled  with  an  alkali  hydroxid,  soaps 
are  formed  and  glycerol  is  set  free : 
C.7H35COO— CH,         KOH         Cx7lI,,sCO()lv         CH.OH 

Cz7H3,COO— CH    +  KOH   =   CivHj.CQOK   +    CHOH 

C.7H,.COO-CH,         KOH         C,^H,„COOK         CH.OH 

tristearin  potassium  ttearate      glycerin. 

(soft  soap) 

From  the  above  it  will  be  seen  that  soaps — scdium 
or  j)()tassium  oleate  or  stearate — arc  sails  oj  the  jalfy 
acids.  Potassium  stearate  is  very  deliquescent.  It 
takes  up  water  from  the  air  and  is,  therefore,  termed 
"soft  soap";  sodium  stearate  is  not  de]i(iuesi-ent  and 
constitutes    the    hard    soaps   of    the    market.     Some 


NITROGLYCEROL.  289 

salts  of  these  acids,  such  as  calcium  or  magnesium, 
are  insoluble  in  water,  and  they  must  all  be  precipi- 
tated before  the  soap  will  act  as  a  detergent.  This 
is  the  reason  why  the  use  of  soaps  in  laundering 
is  attended  with  great  waste  of  soap.  Hard  waters 
for  laundry  purposes  may  be  rendered  soft  by  precipi- 
tating these  compounds  and  decanting  the  so-softened 
water.  One  method  of  accomplishing  this  is  to  add 
about  one  grain  of  alum  per  each  gallon  of  water, 
stirring  it  well  and  letting  it  stand  for  some  little 
time,  when  the  aluminum  hydroxid  and  carbonate 
formed  therein  will  slowly  subside,  carrying  with  it  all 
of  the  inorganic  "hardening  salts"  in  solution,  in  the 
water. 

Glycerol  forms  salts  with  nitric  acid,  of  which  the 
trinitrate  is  the  most  important. 

Trinitrin,  nitroglycerin,  glonoin,  Nobel's  oil. 
C3H5(ON02)3.  Trinitrin  was  discovered  by  Sobrero 
(1841),  but  was  first  applied  practically  by  Nobel 
(1867).  Nitroglycerin  is  prepared  by  mixing  12 
parts  of  fuming  nitric  acid  v/ith  20  parts  of  sulfuric 
acid,  and  running  into  this  well-cooled  mixture  a 
very  thin  stream  of  glycerol,  which  is  forced  in  by 
a  current  of  air.  The  sulfuric  acid  serves  here  as  a 
dehydrating  agent: 
C3H,(OH)3  +  3HNO,  =  C3H,(ONQJ3  -f  3H2O. 

trinitrin 

The  mixture  is  diluted  with  water,  the  nitrogly- 
cerin separates  in  oily  drops  or  layer,  which  is  care- 
fully washed  with  water  to  separate  the  glycerin, 
and  next  with  a  weak  solution  of  soda  to  free  it  from 


290  PHARMACEUTIC    CHEMISTRY. 

the  acids.  It  is  then  converted  into  the  manv  ex- 
plosive compounds. 

This  highly  explosive  compound  has  the  ap])ear- 
ance  of  a  yellowish  oil,  which  is  highly  volatile. 

By  warming  nitroglycerin  carefully  and  dissolving 
in  it  collodion-cotton  (nitrocellulose);  upon  cooling, 
the  mixture  solidifies  to  a  jelly-like  consistence. 
This  jelly  is  insoluble  in  water  and  is  well  adapted  to 
many  purposes  where  explosives  are  required.  It  is 
called  explosive  gelatin  or  blasting  gelatin. 

Dynamite  is  made  by  mixing  3  parts  of  nitrogly- 
cerin with  I  part  of  a  fine  silicious  earth,  such  as 
kieselguhr,  which  is  very  porous  and  which  can 
absorb  considerable  quantities  of  nitroglycerin  with- 
out becoming  pasty.  This  mixture  is  moulded  into 
cartridges  or  sticks  and  fired  by  a  detonator,  usually 
made  of  mercury  fulminate.  When  gun-cotton  and 
nitroglycerin  are  made  into  a  pulp  with  acetone  and  a 
little  petrolatum,  cordite  is  formed.  This  pulp  is 
squeezed  through  small  holes  into  tiny  threads 
which,  upon  evaporation  of  the  acetone,  are  used 
after  being  cut  up  for  smokeless  rifle  cartridges. 
When  mixed  with  sawdust,  nitrate  of  potassium  or 
ammonium  nitrate,  various  exj^losivcs  are  formed 
which  are  known  under  such  names  as  jorcite,  vitlcan 
powder,  etc.  The  method  of  manufacture  of  trini- 
trin  is  similar  to  the  formation  of  ethyl  nitrate  from 
ethyl  alcohol,  and,  like  the  latter,  it  can  be  saponified 
by  caustic  alkalis,  showing  that  in  fact  it  is  an  ester 
and  not  a  nitro  comj^ound.  The  name  nitroglycerin, 
therefore,  is  only  used  because  througii  usage  it  has 


THE    FATS.  291 

been  adopted  as  the  technical  name  of  the  compound, 
but  in  fact  it  is  a  misnomer.  Nitroglycerin  is  official 
in  the  Pharmacopoeia  as  a  spirit  (spiritus  glycerylis 
nitratis  U.  S.  P.),  which  contains  1%  by  weight  of 
nitroglycerin. 

THE  FATS. 

In  constitution  the  fats  resemble  nitroglycerin  in 
that  they  are  esters  of  the  higher  fatty  acids.  Thus, 
olive  oil,  cottonseed  oil  and  expressed  almond  oil  are 
chiefly  glyceryl  esters  of  oleic  acid;  palm  oil  is 
chiefly  glyceryl  of  palmitic  acid;  beef  tallow  is  nearly 
pure  glyceryl  stearate,  while  castor  oil  is  glyceryl 
ricinoleate;  expressed  oil  of  nutmeg  (nutmeg  butter) 
is  chiefly  glyceryl  myristicate.  Again,  expressed 
laurel  oil  is  glyceryl  laurinate  and  butter  is  glyceryl 
butyrate.  These  glyceryls  are  the  proximate  prin- 
ciples of  these  various  fats  and  are  collectively  known 
as  fats.     The  important  fats  are: 

Laurin,  C3H5(Ci2H,302)3,  its  acid  =  HC12H23O2  = 
lauric  acid. 

Myristin,  C3H5(Ci,H.,70,)3,  its  acid  =  HCi.H^.O^ 
=  myristic  acid. 

Palmitin,  C3H5(C\eH3iO.,)3,  its  acid  =  HCigH3iO 
=  palmitic  acid. 

Olein,  C3H5(Ci3H330,)3,  its  acid  =  UC,,U,,0,  = 
oleic  acid. 

Stearin,  C3H5(Ci,H3,(),)3,  its  acid  =  HC,sH3502 
=  stearic  acid. 

Liquid  fats  consist  almost  entirely  of  olein;  olive 
oil,  cottonseed  oil  and  expressed  oil  of  almonds  are 


292  IMIAKMACKUTIC    CHKMISTKV. 

examples  of  pure  olcin.  They  are  sometimes  called 
fatty  or  fixed  oils,  to  distinguish  them  from  the  es- 
sential, volatile  or  ethereal  oils. 

Solid  fats  contain  a  larger  proportion  of  palmitin 
and  stearin;  it  might  be  said  that  the  relative  pro- 
|K)rtion  of  each  of  the  three  glyceryls  (palmitin  and 
stearin  are  solids,  olein  a  liquid)  ]>resent  in  the 
fat  determines  its  consistency  and  other  ])hysicai 
properties. 

CoDiposition. — The  animal  fats  consist  })rincipally 
of  a')out  8o'/o  <^>f  the  glyceryl  esters  of  the  higher  fatty 
acids  (stearic,  palmitic  and  oleic)  and  about  2o9c 
of  th'e  esters  of  the  lower  fatty  acids  and  sometimes 
the  esters  of  the  higher  alcohols.  The  proportion  of 
these  esters  varies  with  the  sources  of  the  fats. 

Properties. — The  solid  fats  melt  below  100°  C. 
and  can  be  distilled  at  about  300°  C.  with  a  slight 
decomposition.  At  higher  temi)eratures  they  are 
decomposed  into  acrolein.  When  pure  they  are 
colorless,  odorless  and  tasteless.  They  are  insoluble 
in  water,  sparingly  in  cold  alcohol,  but  freely  in  ether, 
chloroform,  benzene  and  carbon  disulfid.  They  all 
have  a  lower  specific  gravity  than  water.  Upon 
standing,  by  a  decomposition  peculiar  to  the  fats 
alone  and  due  perhajjs  to  oxidation  or  fermentation 
(and  maybe  to  both),  fats  ac(juire  color  and  taste. 
These  are,  therefore,  products  of  decomposition. 
The  disagreeable  odor  and  taste  of  fats  (rancidity)  is 
due  to  the  fatty  acid  which  is  liberated.  Such  rancid 
fats,  when  heated  with  sodium  carbonate  solution, 
are  der)rivcd  of  their  disagreeable  oflor. 


I'RKPARATIOX  AND    ADULTERATION    Ol'    J  ATS.    293 

The  liquid  fats  all  have  a  specific  gravity  lighter 
than  water,  but  when  exposed  to  lower  temperatures, 
they  become  partly  solid  (lard  oil),  and  through  such 
reduction  of  temperature  some  of  the  principles  may 
be  separated  from  the  others. 

Preparation. — Animal  fats  are  prepared  from  the 
tissues  by  melting  them  alone  or  in  the  presence  of 
water  and  separating  the  fused  fat  by  straining. 
Many  of  the  vegetable  oils  are  prepared  by  expres- 
sion, sometimes  by  extraction  with  a  volatile  solvent, 
such  as  petroleum  benzin,  carbon  tetrachlorid,  etc., 
while  inferior  oils  are  obtained  by  boiling  the  material 
with  water,  decanting  the  floating  oil  from  the  refuse 
matter  and  straining. 

Adulteration. — Fats  are  very  prone  to  adulteration 
with  commoner  or  cheaper  varieties.  Owing  to  the 
similarity  in  composition,  the  adulterants  are  difficult 
to  detect.  The  principal  means  of  detection  of  the 
fraud  is  by  the  odor,  which  is  peculiar  upon  warming, 
by  the  color  reaction  with  acids  or  silver  nitrate  and 
by  the  boiling-  and  melting-points.  Fish  oils  (a 
frequent  adulterant)  are  detected  in  the  vegetable  oils 
by  passing  chlorin  gas  through  the  oil.  In  the 
presence  of  jish  oils,  the  fat  will  turn  dark.  Sulfuric 
acid,  when  heated  with  ten  parts  of  the  oil,  produces 
different  colorations,  depending  on  the  nature  of  the 
oil,  and  serves  as  a  means  of  identifying  the  same. 
Thus,  with  oil  of  black  mustard,  a  bluish-green  color 
is  acquired;  with  fish  oil,  a  reddish  color;  and  with 
linseed  oil,  a  dark  brown.  The  identity  and  purity 
of   fats   may   be   determined  quantitatively   by   the 


294  PHARMACEUTIC    CHKMTSTRY. 

"saponification  value."  This  dc])ends  upon  the 
number  of  cubic  centimeters  of  alcoholic  potash 
required  to  neutralize  a  weighed  quantity  of  the 
oil.  The  other  test  is  the  determination  of  the  "iodin 
number,"  which  depends  on  the  determination  of 
the  percentage  of  iodin  solution  absorbed  by 
the  fat. 

In  the  case  of  vegetable  fats,  the  presence  of  pro- 
tein or  mucilaginous  substances  tends  to  rancidify 
them.  These  impurities  may  be  removed  by  filtra- 
tion or  by  treatment  with  2%  sulfuric  acid.  The 
acid  is  gradually  added  to  the  fat  in  which  it  carbon- 
izes the  impurities  and,  after  separating  the  acid  and 
repeated  agitation  with  water  to  wash  away  the  last 
traces  of  it,  the  fat  is  subjected  to  filtration. 

Fats  should  be  preserved  in  perfectlv  dry,  her- 
metically sealed  vessels  and  in  a  cool  place. 

Beef  tallow,  mutton  suet  and  lard  are  mixtures  of 
stearin,  palmitin  and  olein.  In  the  first  fat,  stearin 
predominates;  and  in  the  last  fat,  olein. 

Butter  is  a  complex  mixture  .of  the  glycerids  of 
butyric,  caproic,  caprylic,  capric,  myristic,  palmitic 
and  stearic  acids.  The  first  four  of  the  above  esters 
constitute  about  12%  of  butter.  They  are  volatile 
with  water  vapor  and  can  be  separated  from  the 
other  constituents  of  butter  by  distilling  with  steam. 
Butter  is  made  from  the  cream  of  cow's  milk  by  the 
process  of  churning.  When  of  good  quality,  it 
should  contain  about  90%  of  fat,  8%  of  water,  1%  of 
curd  and  1%  of  salt.  As  said  before,  butter  consists 
mainlv  of  stearin,  with  about  7''-'   of  l)Ut\rin.     The 


BUTTER    MANUFACTURE.  295 

purity  of  butter  may  be  roughly  determined  by  saponi- 
fying a  weighed  quantity  with  caustic  soda,  acidify- 
ing with  sulfuric  acid  and  distilling.  The  volatile 
fatty  acids  which  distill  over  are  estimated  by  titration 
with  alkali  hydroxids.  The  water  is  determined  by 
drying  a  weighed  sample  of  butter  n  a  hot-water 
oven  to  a  constant  weight.  The  salt  and  curd  may 
be  determined  by  melting  and  passing  through  a 
weighed  filter,  washing  the  filter  with  ether  until  free 
from  fat.  The  curd  and  salt  remain  upon  the  filter, 
and  the  salt  is  estimated  by  igniting  the  filter,  burning 
off  the  organic  matter,  and  the  curd  by  difference. 
Old,  rancid  butter  may  be  deprived  of  its  rancidity  by 
heating  it  and  treating  with  a  solution  of  sodium 
carbonate  and  afterward  by  kneading  it  with  sweet 
milk,  which  latter  serves  two  purposes:  first,  to 
wash  away  the  traces  of  the  alkali  present,  and, 
second,  to  impart  a  sweet-milk  flavor  to  the  butter. 
Such  is  the  method  of  making  "renovated  butters." 
Renovated  butters  may  be  readily  detected  by 
heating  them  slightly  in  a  test-tube,  when  the  rancid 
odor  will  at  once  appear;  and  upon  higher  heating,  a 
frothing  will  occur  with  a  peculiar,  crackling  sound. 
Since,  as  an  article  of  diet,  butter  is  rather  high- 
priced,  many  so-called  "butter  substitutes  "  have  been 
offered.  Of  these  margarin,  oleomargarin,  butterin 
and  cottosuet  are  the  familiar  commercial  examples. 
These  are  prepared  by  melting  beef  tallow  or  suet 
and  heating  to  a  temperature  of  35°  and  subjecting 
to  pressure.  The  lower  melting  portion,  which  is 
expressed,  contains  a  large  quantity  of  olein,  to  which 


296  PHARMACEUTIC    CHEMISTRY. 

the  name  "oleo  oil"  has  been  gi\en.  This,  wlu-n 
mixed  with  eottonseed  oil  and  a  little  milk  and 
genuine  butter,  upon  chilling,  constitutes  oleomar- 
garin.  The  butter  substitutes  can  be  identitied  by 
the  fact  that  the  volatile  fatty  acids  (butyric  acid)  are 
always  considerably  below  that  of  the  genuine 
butter  (4-5-5 %)•  The  melting-points  of  the  two 
articles  also  vary  considerably.  When  properly 
prepared,  margarin  is  a  perfectly  wholesome  article 
of  food  and  in  chemical  composition  ver\-  similar  to 
butter. 

Wool-jilt,  also  called  wool-grease,  Yorkshire 
grease,  and  its  purilied  varieties,  known  under  the 
fanciful  name  of  "lanolin"  (adeps  lanae,  and  adeps 
lan^e  hydrosus  U.  S.  P.),  constitute  the  oflacial  fat 
from  sheep's  wool.  It  is  prepared  by  scouring  wool 
Chemically,  it  is  a  complex  mixture  of  the  fatty 
acids  with  cholesterol,  an  alcohol  having  the  formula 
^6^44^-  It  is  separated  from  the  wool  washings 
by  adding  sulfuric  acid,  which  causes  the  "cracking," 
or  raising  the  greasy  matter  to  the  surface,  when  it  is 
skimmed  off.  It  comes  into  the  market  in  a  brown, 
semi-solid  mass  which,  upon  trituration  with  water, 
forms  a  straw-colored  emulsion  known  as  the  hy- 
drated  wool-fat  or  "  lanolin."  The  cholesterin  is  capa- 
ble of  absorbing  more  than  its  own  weight  of  water,  it 
resists  saponification  and  does  not  rancidify.  It  has 
also  the  property  of  penetrating  the  skin  and  is, 
therefore,  preferable  to  the  other  unguents.  Cacao 
butter,  obtained  by  expressing  roasted  chocolate  nuts, 
is    known   in   [)harmacy  as  a   yellowish-colored   fat. 


LIQUID    FATS   AND    THE    WAXES.  2Q7 

melting  at  30  to  35  °C.  to  a  clear  liquid,  and  having 
a  specific  gravity  of  0.97.  Chemicall}-,  it  is  a  mix- 
ture of  olein,  palmitin,  stearin,  arachin  and  laurin. 
It  is  used  for  making  suppositories  and  ointments 
(oleum  theobromatis  U.  S.  P.). 

Liquid  fats  are  classified  into: 

{a)  Drying  oils;  this  group  embraces  poppy, 
linseed,  hemp  and  nut  oils. 

{b)  Nondrying  oils;  olive,  almond,  rape,  colza, 
lard,  tallow  and  neatsfoot  oils.  (The  first  four  are 
vegetable.) 

(r)  Inte'rmediate  oils  (which  possess  some  prop- 
erties of  each  of  the  above  two  classes.  These 
embrace  codfish  oil,  cod-liver  oil,  sperm,  hake,  por- 
poise, shark  and  whale  oils.  This  is  the  so-called 
fish-oil  group.  To  the  cottonseed  oil  group  belong 
cottonseed  oil,  sunflower,  beechnut  and  teel  oils. 
Besides,  the  two  alcohol-soluble  oils — castor  oil  and 
croton  oil,  are  classed  here. 

All  oj  the  above  fats  when  saponified  yield  soaps  and 
glycerin. 

The  Waxes.— This  is  a  division  of  the  fats  consisting 
of  those  which,  on  saponification,  yield  no  glycerin, 
but  do  yield  complex,  monatomic  alcohols.  All 
waxes  are  solid  at  the  ordinary  temperature,  and  they 
include  beeswax,  which  may  be  bleached  by  exposing 
it  to  light;  Chinese- wax,  Brazilnut  wax,  myrtle  wax, 
palm  wax  and  spermaceti,  the  last  obtained  from 
deposits  in  the  head  cavities  of  the  sperm-whale. 

Manufacture  of  Candles. — Stearic  acid,  which  we 
commonly  call  stearin,  is  used  in  the  production  of 


298  PHARMACKUTIC    CHEMISTRY. 

candles.  After  tristearin  is  hvdrolyzed  with  su])er- 
heated  steam,  pure  stearic  acid  is  obtained,  this  after 
separation  from  glycerin,  is  afterward  pressed  while 
hot  to  remove  the  liquid  oleic  acid,  and  to  produce  the 
harder  and  firmer  stearic  acid.  Stearic  acid,  after 
mixing  with  a  little  paraffin  wax,  is  moulded  into 
candles.  Sometimes  paraffin  wax  with  a  mixture 
of  but  a  trace  of  stearic  acid  is  used  for  the  same 
purpose. 

Varnishes. — Among  the  drying  oils,  pop]\v  oil  and 
linseed  oil  were  mentioned.  These  oils,  when  ex- 
posed to  the  air,  oxidize  slowly,  forming  a  hard 
varnish.  The  absorption  of  oxygen  from  the  air  by 
these  oils  can  be  made  to  take  place  much  more 
rapidly;  thus:  By  boiling  the  drying  oils  with  lead 
oxid,  manganese  dioxid  or  oxalate,  these  take  up  all 
of  the  oxygen  and  are  converted  into  "boiled  oils," 
also  called  "quick-drying  oils."  When  linseed  oil  is 
boiled  with  resins  or  "varnish  gums,"  as  they  arc 
sometimes  called,  such  as  kauri  gum,  copal  gum  or 
dammar  gum,  varnishes  are  produced.  Wirnishes 
are  sometimes  thinned  by  turpentine,  benzin  or 
alcohol. 

Allied  Products. — As  glycerin  is  a  ])roduct  of  the 
fats,  so  allyl  alcohol  is  also  a  product  of  glycerin. 
When  glycerin  is  heated  with  oxalic  acid,  two  of  the 
OH  groups  are  removed,  according  to  the  following 
formula: 

C3H5(()H)3   +    (COOH),   =  C3H,— OH    +2C(X 

allyl  alcohol 
+    2H..O. 


ACROLEIN.  299 

giving  rise  to  allyl  alcohol,  to  whicli   the  following 
graphic  formula  has  been  ascribed: 

CH. 

II    ' 
CH 

I 
CH,OH 

When  allyl  alcohol  is  subjected  to  further  oxidation, 
the  remaining  primary  alcohol  group  is  oxidized  and 
an  aldehyd  called  acrolein  is  formed: 

CH.. 

II    " 
CH 

I      O 

K 

^H 

Acrolein  is  a  liquid  possessing  a  pungent  odor  and 
is  a  constituent  of  the  acrid  fumes  from  burning  fat. 
When  acrolein  is  subjected  to  oxidation,  acrylic  acid 
is  formed,  to  which  the  following  graphic  formula 
has  been  ascribed: 


CH 

OH 

When  all  three  hydro.xyl  groups  of  glycerin  have 
been   replaced   by   oxidation   with    COOH   groups, 


300  I'HARMACKUTIC    CHKMISTRY. 

Irkarhallylic  acid,  to    which  the    following  graphic 

formula  has  been  ascribed,  is  formed: 

CH,.COOH 

1 
CH.COOH 

I 
CH2COOH 

This  acid  is  chemically  interesting  from  the  fact  that 
its  hydroxyl  derivative,  which  has  also  been  obtained 
from  glycerin,  is  the  very  important  citric  acid. 

CITRIC  ACID,  HaCeH-O;,  exists  naturally  in  the 
fruits  of  the  members  of  the  orange  family,  such  as 
lemons,  limes,  oranges,  etc. 

Mail II fact  11  re  0}  Citric  Acid. — On  a  large  scale,  the 
lemon  peel  is.first  grated  off  and  from  it,  by  solution 
with  petroleum  ether,  oil  of  lemon  is  obtained.  The 
lemons  are  then  sliced,  their  juice  expressed  and  sub- 
jected to  boiling.  In  the  process  of  boiling  the  al- 
buminous and  mucilaginous  principles  are  coagulated 
and  can  be  removed  by  filtration.  To  the  filtered 
aqueoussolution  lime-water  is  added,  which  neutral- 
izes the  juice  and  forms  calcium  citrate.  By  adding 
to  the  solution  of  calcium  citrate  sulfuric  acid,  the 
salt  is  decomposed  and  citric  acid  is  liberated.  It  is 
then  subjected  to  filtration  to  free  the  liquid  from  the 
insoluble  calcium  sulfate.  The  liquid  is  further 
evaporated  to  a  small  bulk  and  permitted  to  crystal- 
lize. Citric  acid  should  be  carefully  examined  for 
the  presence  of  calcium  sulfate  and  free  sulfuric  acid 

Other  Polyatomic  Alcohols.— Besides  glycerin,  an- 
other triatomic  alcohol  is  known,  namely,   pentcnyl 


ARTARIC   ACID. 


301 


alcohol,  C5H9(OH)3,  also  called  amyl  glycerin. 
Eryfliritol,  C^Hg(OH)„  is  a  tetratomic  alcohol  found 
in  certain  lichens.  It  is  of  little  importance,  but  the 
dibasic  acid  corresponding  to  it  is  very  important. 

TARTARIC  ACID  is  a  dibasic  and  diatomic  acid 
and  exists  in  four  different  physical  modifications. 
The  chief  difference  in  these  modifications  is  found  in 
the  crystalline  form  of  the  salts  produced  from  them 
and  in  the  behavior  of  their  solution  when  viewed 
with  polarized  light.  The  four  kinds  of  tartaric 
acid  known  are: 
(i)  Dextrotartaric  acid     (the  acid  in  ordinary  use). 

(2)  Levotartaric  acid. 

(3)  Racemic  acid  (a  mixture  of  equal  weights 

•  of  the  dextro-  and  levo- 

modifications ;    inactive, 
but  efflorescent). 

(4)  Mesotartaric  acid       (inactive,      and     obtained 

by  heating  the  ordinary 
dextro  acid  with  a  small 
quantity  of  water) . 
The  graphic  relations  of  the  four  acids  may  be 
shown  by  the  following  structural  formulas: 

(i)     '    (2)  (3)         (4) 

COOH     COOH      COOH      COOH 

I  i  I  I 

CHOH     CHOH  HOHC     HOHC 

I    -     I    -      I    -     I 
CHOH  HOHC  CHOH  HOHC 

I  I  'I  I 

COOH     COOH      COOH      COOH 

When  speaking  of  tartaric  acid   we  said  it  was 


302  I'lfARMACEUTIC    CHEMISTRY. 

dibasic  and  diatomic.  The  basisity  of  an  organic 
acid  is  reckoned  by  the  number  of  the  carboxyl 
( — COOH)  groups  it  contains,  while  the  atomicity  of 
an  acid  is  reckoned  by  the  number  of  hydro.wl 
( — OH)  groups  it  contains  in  addition  to  the  carboxyl 
groups.  Thus,  we  observe  that  the  tartaric  acids 
contain  in  their  graphic  formulas  two  carboxyl  and 
two  hydroxyl  groups  and  are,  therefore,  dibasic  and 
diatomic,  while  citric  acid  contains  three  carboxyl 
groups  and  one  hydroxyl  group  and  is,  therefore, 
spoken  of  as  tribasic  and  monatomic: 


(COOH) 
CH(OH) 

CH2(C00H) 
C(OH)  (COOH) 

CH(OH) 
(COOH) 

A  dibasic  diatomic 
acid  (tartaric) 

CH2(C00H^ 

A  tribasic-monatomic  acid 
(citric) 

(The  different  groups  will  be  found  in  i)arentheses.) 
Tartaric  acid  occurs  in  nature  chiefl\-  as  impure 
potassium  bitartrate,  or  cream  of  tartar,  commercially 
known  as  argols.  It  is  deposited  during  the  process  of 
fermentation  in  the  form  of  a  brown,  crystalline 
crust,  also  called  "wine-lees."  It  was  ist)lated  by 
Scheele  (1769),  and  is  found  widely  distributed  in 
fruits.  With  malic  acid  it  is  found  in  the  berries  of 
mountain  ash,  and  is  also  found  in  gooseberries, 
raspberries,  strawberries,  its  main  source  being  grape 
juice. 

When  gra|)C'  juice  is  subjected  to  fermentalion,  the 
alcohol    whicli    forms    in    the    process    renders    the 


PREPARATION    OF    TARTARIC   ACID.  303 

potassium  salt  of  tartaric  acid  insoluble,  and  this 
deposits  in  minute  crystals  on  the  sides  and  bottom 
of  the  vat.  The  brown  powder  dissolved  in  water, 
filtered  through  bone-black,  the  solution  evaporated 
and  allowed  to  crystallize,  constitutes  "cream  of 
tartar."  Both  tartaric  acid  (acidum  tartaricum 
U.  S.  P.)  and  potassium  bitartrate,  "cream  of  tar- 
tar" (potassii  bitartras  U.  S.  P.),  are  official;  the 
first  is  required  of  99.5%,  the  latter,  99%  purity. 

•  Tartaric  acid  is  prepared  from  argols  by  dissolving 
it  in  water  and  neutralizing  with  chalk.  The  insol- 
uble calcium  tartrate  which  deposits  by  filtration 
is  separated  from  the  neutral  potassium  tartrate 
which  remains  in  solution.  The  solution,  by  being 
treated  with  calcium  chlorid,  gives  a  further  yield  of 
the  acid.  The  entire  process  is  represented  in  the 
following  equations: 

(i)  2KHC,H,Oe  +  CaCOg  =  CaC.H.Og  + 
KjC.H.Oe  +  CO,  +  H^O. 

(2)   K^C.H.O,  +  CaCU  =  CaC,H/:»,  +  2KCI. 

The  solution  of  calcium  tartrate  is  next  decomposed 
by  sulfuric  acid,  filtered  from  the  insoluble  calcium 
sulfate,  concentrated  by  evaporation  and  allowed  to 
cool,  when  crystallization  will  take  place.  The 
potassium  chlorid  is  recovered  as  a  by-product  and 
employed  in  the  manufacture  of  potassium  salts. 
Tartaric  acid  occurs  in  large  prisms,  is  freely  soluble 
in  water  and  alcohol  and  has  a  melting-point  of 
135  °  C.  When  subjected  to  dry  distillation,  pyro  tar- 
/  /;7V(/r/rf— (methyl  succinic  acid,)  CH^— CH(CX)OH) 
— CH,(C()OH)— is   formed. 


304  IMIARMACEUTIC    CHEMISTRY 

The  official  salts  of  tartaric  acid  are  "Rochelle 
salts"  and  "tartar  emetic." 

Rochelle  salt  is  chemically  potassium  and  sodium 
tartrate — a  double  salt  occurring  in  transparent 
prisms  or  a  white  powder,  soluble  in  1.2  parts  of 
water.  It  is  prepared  by  adding  cream  of  tartar  to 
a  solution  of  sodium  bicarbonate.  The  operation 
should  be  carried  on  carefully,  owing  to  the  evolution 
of  carbon  dioxid  gas,  until  the  first  solution  is  neu- 
tralized. It  is  next  filtered,  evaporated  and  allowed 
to  crystallize.     The  following  reaction  takes  place: 

KHC,H,0,  +  NaHCOj  =  KNaC.H.Og  +  CO, 
4-  H,0. 

Rochelle  salt  (potassii  et  sodii  tartras  U.  S.  P.)  is  an 
ingredient  in  the  official  compound  effervescent  pow- 
der (seidlitz  powder).  It  is  sometimes  called  "Seig- 
nette's  salt"  after  its  discoverer,  Seignette  de  la 
Rochelle. 

Tartar  emetic  (anlimonii  et  potassii  tartras  U.  S.P.) 
is  the  potassio-stibyl  tartrate,  an  acrid  salt,  crystal- 
lizing with  half  a  molecule  of  water;  soluble  in  water 
and  prepared  by  dissolving  antimonous  oxid  in  a 
solution  of  cream  of  tartar: 

Sb,0 ,  -f  2KHC4H4O6  =  2KSbOC4H,06  -1-  H,0 
potassio-stibyl 
tartrate. 
COOK 
I 
CHOH 

=      I 

CHOH 

I 
COO-^Sb  =  0 

Tartar  emetic  is  a  stroiiLr  poison.     The  best  anti- 


BAKING    POWDERS.  305 

dote  is  tannic  acid  or  any  substance  containing  it. 
Baking  Powders. — These  usually  are  mixtures  of 
cream  of  tartar  with  sodium  bicarbonate  and  starch 
or  other  dry  material  which  serves  the  purpose  of  a 
'iiUer"  and  acts  as  an  absorbent  of  any  moisture, 
thus  preventing  the  liberation  of  any  free  carbon 
dioxid.  The  baking  powder  is  added  to  flour  and 
stirred  with  water,  forming  dough.  This  operation 
liberates  the  carbon  dioxid  which,  in  the  process  of 
baking,  is  evolved,  making  the  bread  porous  and 
spongy.  The  reaction  which  takes  place  is  identical 
with  the  one  exhibiting  the  formation  of  Rochelle 
salt.  Since  sodium  carbonate  is  harmful,  its  excess 
in  baking  powders  should  be  carefully  avoided.  A 
good  baking  powder  can  be  made  by  carefully  drying 
cream  of  tartar  and  sodium  bicarbonate  and  mixing 
these  with  starch  in  the  following  proportions:  cream 
of  tartar,  4;  sodium  bicarbonate,  2;  starch,  ^  part. 
Alum  is  sometimes  found  a  constituent  in  commercial 
baking  powders,  this  in  the  presence  of  sodium  bicar- 
bonate forms  the  injurious  and  insoluble  aluminum 
hydroxid  with  the  evolution  of  carbon  dioxid.  Alum 
baking  powders  should  be  guarded  against. 

Calcium  diphosphate  with  sodium  bicarbonate 
frequently  forms  the  addition  to  the  so-called  "self- 
rising"  flours. 

The  reactions  of  the  three  classes  of  baking  potvders  : 
(i)   Cream  of  tartar  with  a  bicarbonate  reacts  thus : 
KHC.H.O^    +    NaHCOg    =    NaKC^H.O,    + 
H,0  -f  CO2. 
Rochelle  salts  being  formed. 


3o6  PHARMACiaiTlC    CHKMISTRY 

(2)  Alum  powders  react  as  follows: 
2AlK.(SO,)2  +  6NaHC03=  K,SO,+  2Al(OH)3  + 

3Na2SO,  +  6CO,. 

Aluminum    hydrate    and    sulfates   of    sodium   and 

potassium  being  formed. 

(3)  The  acid-phosphate  powders  react  as  follows: 
CaH,(POj,  +  2NaHC()3  =  CaHPO,  +  Na,HPO, 

+  2H,0  +  2CO2. 

Hydrocalcium  phosphate  and  sodium  jjhosphate  are 

produced  in  the  reaction. 

Arahitol  and  Xylitol,  C5H7(OH)5,  are  both  pen- 
tatomic  alcohols,  both  obtained  by  reducing  their 
corresponding  aldehyds;  arabinose,  a  constituent  of 
gum  arable;  and  xylose,  a  wood  gum  obtained  from 
various  trees  by  digestion  with  caustic  alkali  and 
precipitation  with  alcohol.  /\mong  the  hexatomic 
alcohols  are  classed  mannitol,  dukitol  and  sorbitol, 
CgHg(OH)g,  all  found  in  the  different  species  of  ash; 
they  all  contain  a  straight  chain  of  carbon  atoms. 

Synthesis  oj  the  Alcohols.— {1)  Methyl  alcohol  may 
be  synthetized  by  treating  methyl  halid  with  potas- 
sium hydroxid: 

CH3I    +    KOH    =    CH3OH    +    KI 

Ethyl  alcohol  may  be  synthetized  from  its  elements 
as  follows: 

(a)  C2  +  H2  =  C2H2  =  acetylene. 

(b)  C2H2  +  H2  =  C2H,  =  ethylene. 

(c)  CjH,  4-  H2SO,  =  C2H5HSO,  =  ethyl  sulfuric 
acid. 

id] 
alcohol. 


SYNTHESES    OF    THE   ALCOHOLS.  307 

(2)  Ethyl  alcohol  may  be  produced  from  methyl 
alcohol  by  converting  the  latter  with  phosphorus 
iodid  into  a  methyl  halid,  two  molecules  of  which 
treated  with  two  molecules  of  potassium  hydroxid 
split  into  two  molecules  of  potassium  iodid,  water  and 
ethyl  alcohol;  thus: 

(a)  3CH3OH  +  PI3  =  3CH3I   +  P(OH)3. 

{b)  2CH3I  +  2KOH  =  2KI  +  H2O  +  C2H5OH. 

A  third  method  of  synthesis  is  by  converting  the 
alkyl  halids  with  potassium  cyanid,  which  reaction 
yields  alkyl  cyanids,  called  nitrils.  When  a  nitril  is 
treated  with  zinc  and  hydrochloric  acid,  it  is 
reduced  to  ethyl-amin.  This  can  be  diazotized  by 
treating  with  nitrous  acid,  yielding  ethyl  alcohol, 
water  and  nitrogen,  as  follows: 

{a )  CH3I  +  KCN  =  CH3— C  =  N,  methyl  cyanid,  + 
KI. 

(b)  CH3CN  +,  Zn,  +  4HCI  =  CH3CH2NH,, 
ethyl  amin,  +  2ZnCl2. 

(f)  CH3CH2NH2  +  HNO2  =  CHgCHjOH, 
ethyl  alcohol,  +  N,  +  HjO. 

This  reaction  is  a  very  important  one  in  that  we 
may  pass  from  a  one-carbon-atom  compound  to  a 
two-atom-carbon  compound,  and  from  a  two-carbon 
to  a  three-carbon  compound,  etc.  By  this  method 
of  synthesis  we  can  build  up  very  complex  compounds 
from  simpler  ones. 

Methyl  cyanid  may  be  obtained  directly  by  heating 
ammonium  acetate  with  phosphorus  pentoxid,  and 
for  this  reason  it  is  frequently  called  aceto-nitril. 

Secondarv  and  tertiary  alcohols  mav  be  svnthetized 


3o8  PHARMACEUTIC    CH  li.MISTRY. 

as  follows:  When  acetaldehyd  is  heated  with  zinc 
alkyl.  compound,  the  zinc  atom  of  the  latter  attaches 
itself  to  the  oxygen  atom  by  one  bond,  losing  at  the 
same  time  an  alkyl  group  which,  in  turn,  is  trans- 
ferred to  the  unsaturated  carbon  atom  of  the  same 
group.  The  ])roduct  is  subsequently  decomposed 
with  water,  forming  the  alcohol;  thus: 

CH3CHO  +  Zn(CH,),  =  CH3  — CHOH  — CH3  + 

acetaldehyd  secondary  propyl  alcohol 

ZnO  +  CH,. 

When  ketones  are  treated  with  zinc  alkyl  com- 
])ounds,  tertiary  alcohols  are  formed;  thus: 

CH, 

I 
CH,— C()--CH,+Zn(CH,),  =  CH;-^C— OH+ZnO+CH, 

dimethyl  ketone  | 

CH, 
tertiary  biitvl 
alcohol.   ■ 

Secondary  alcohols  may  also  he  synthetizcd  by 
means  of  the  magnesium  alkyl  compounds  by  what  is 
known  as  "Grignard's  reaction."  When  an  alkyl 
bromid  or  iodid  reacts  with  magnesium  in  the 
l)resence  of  ether,  correspontling  magnesium  alkyl 
l)romid  or  iodid  is  formed.     Thus: 


.\ig  +  cH,i  =  y^g^j^' 


magnesium  methyl 
iodid 


The  magnesium  alkyl  compounds  are  decomposed 
by  water  and  form  paraffins.  With  aldehyds 
ketones    and    esters,    etc.,    when    decomposed    with 


FORMATION    OF    SFXONDARY    ALCOHOLS.  309 

water,   they    form    secondar)-   and    tertiary    aUohols 
and  ketones;  thus; 

/CH3 
(i)  CH3CHO  +  CH3MgI  =  CH  — CH 

^OMgl 

intermediate  magne- 
sium compound 

/CH,     •  /CH, 

(2)  HOH+CH3— CH  =CH3— CH         +Mg( 

\                                \  \OH 

^OMgl     ^OH 


secondary  propyl       magnesium 
alcbhol  oxiodid 


CHAPTER  XXVI. 
THE    CYANOGEN    COMPOUNDS. 

CYANOGEN,  C,N,  (from  kyanos,  blue,  and 
gennao,  to  generate,  due  to  the  fact  that  some  of  the 
double  cyanids  possess  a  brilliant  blue  color),  was 
first  prepared  by  Gay-Lussac,  who  made  it  by  heat- 
ing either  mercuric  or  silver  cyanids: 

(i)  Hg(CN),  =  Hg  +  (CN), 

mercuric 
cyanid 

(2)   2AgCN  =  Ag..  +  (CN), 

silver 
cyanid 

Cyanogen  is  a  colorless  gas  with  a  characteristic 
odor  resembling  thaf  of  the  essential  oil  of  hitter 
almonds;  it  is  very  solul^le  in  water  and  very  poison- 
ous. It  is  combustible,  burning  with  a  pink  flame, 
producing  carbon  dioxid  and  free  nitrogen.  Its 
specific  gravity  is  26  and  its  formula  {C'N)^  is  often 
written  Cy. 

Te:it. — The  odor  of  the  gas  and  the  peculiar  pink 
color  of  the  flame  serve  as  the  best  means  for  the 
recognition  of  cyanogen.  Dissolved  in  water,  it 
forms  a  very  poisonous  acid  which  in  its  dilute  form 
— 2%  strong — is  official  (acidum  hydrocyanicum 
dilutum  U.  S.  P.).  It  is  prepared  by  fi eating 
])otassium  cyanid  witli  dilute  sulfuric  acid;  thus: 

2KCN     +     H,S(),     =     2HCN     +     K,S(),. 
310 


POTASSIUM    I'ERROCYANID.  3II 

This  acid  was  first  discovered  by  Scheele  (1782), 
who  prepared  it  from  Prussian  blue  by  distilling  it 
with  a  mineral  acid.  He  correspondingly  called  it 
"prussic  acid,"  which,  however,  contains  4%  of  the 
anhydrous  acid,  and  is,  therefore,  twice  as  strong  as 
the  official  dilute  acid.  In  cases  of  poisoning  the 
best  antidotes  are  mild  inhalations  of  ammonia  or 
chlorin,  the  application  of  cold  water  to  the  head  and 
spine  and  the  ingestion  of  the  following  solution  in 
the  order  named:  (i)  Potassium  carbonate,  20 
grains  in  a  fluid  ounce  of  water;  (2)  ferrous  sulfate, 
10  grains  in  a  fluidounce  of  water,  and  tincture 
ferric  chlorid,  i  fluidram;  the  object  of  the  above 
order  being,  first,  to  form  potassium  cyanid;  second, 
the  ferrocyanid  and,  third,  the  ferric  ferrocyanid 
(insoluble).  Upon  standing  HCN  decomposes  into 
ammonium  formate:     HCN  +  2H2O  =HCOO.  NH,. 

POTASSIUM  FERROCYANID,  yellow  cyanid  of 
potash,  yellow  prussiate  of  potash  (potassii  ferrocy- 
anidum  U.  S.  P.),  K,Fe(CN)6,  3H2O.  This  is  pre- 
pared by  heating  potassium  carbonate  free  from 
sulfate  and  introducing  a  mixture  of  iron  filings  and 
charcoal  obtained  from  refuse  matter  rich  in  nitrogen 
(evaporated  blood,  horse  hair,  hoofs  or  horns). 
When  the  carbon  dioxid  and  inflammable  gases 
cease  to  be  given  off,  the  liquid  mass  is  poured  out, 
cooled  and  lixiviated  with  water.  The  resulting 
solution  is  crystallized,  the  crystals  redissolved  in 
water  and  repurified  by  recrystallization. 

DESCRIPTION  AND  PROPERTIES.— The  salt 
occurs    in    large,     lemon-vellow,     soft,  translucent 


312  PHARMACEUTIC    CHEMISTRY 

(T\stals;  odorless,  with  a  sweet  saline  taste,  neutral 
reaction  and  slightly  efflorescent;  soluble  in  four 
parts  of  water,  insoluble  in  alcohol. 

Tests. — Ac^ueous  solutions  of  the  salt  with  ferric 
chlorid  give  dark  blue  precipitates  (Prussian  blue); 
with  ferrous  salts,  bluish-white  precipitates  are 
formed  which  gradually  turn  greenish-blue;  with 
copper  salts,  chocolate-brown  precipitates,  and  with 
lead  acetate,  \vhite  precipitates  are  formed.  The 
salt  should  not  effervesce  with  dilute  sulfuric  acid 
(carbonates) ;  wdth  hydrochloric  acid  and  barium 
chlorid,  only  slight  cloudiness  (limit  of  sulfates). 
Fused  with  potassium  nitrate  and  dissolved  in  water, 
filtered  and  the  filtrate  treated  with  silver  nitrate,  it 
should  give  but  slight  white  precipitate  (limit  of 
chlorids). 

POTASSIUM  FERRICYANID,  red  prussiate  of 
potash,  K3Fe(CN)8.  This  salt  is  made  by  the 
reduction  of  potassium  ferrocyanid  with  chlorin; 
thus: 

2K,Fe(CN)„  +  CI.,  =  2K3Fe(CN)e  +  2KCI. 
A  solution  is  made  of  potassium  ferrocyanid,  the 
chlorin  passed  into  the  liquid  changes  "its  color  from 
yellow  to  red.  It  is  tested  from  time  to  time  with 
ferric  chlorid,  and  when  it  ceases  to  produce  a  blue 
color  with  it,  it  is  concentrated  by  evaporation  and 
crystallized.  On  exposure  to  air  the  salt  decomposes 
into  ferrocyanid.  The  salt  is  not  official  and  is  only 
valued  as  a  test  solution,  producing  with  ferrous  salts 
a  dark  blue  precipitate  (TurnbuU  's  blue) ;  with  copper 
salts,    a    brownish-yellow    precipitate;    with    silver 


IROiV    I'ERROCYANIl).  313 

salts,  orange  precipitates;  with  mercurous  salts, 
reddish-brown;  but  no  precipitates  are  formed  with 
either  ferric,  mercuric  or  plumbic  salts. 

IRON  FERROCYANID,  Prussian  blue,  William- 
son's blue,  Paris  blue,  Fe,(Fe(CN)6)3.  This  salt, 
while  not  official,  is  of  technical  interest.  It  is 
prepared  by  double  decomposition  between  potas- 
sium ferrocyanid  and  a  ferric  salt,  washing  and 
drying  the  precipitate: 

3K,Fe  (CNje  +  2Fe2(SO,)3  =  Fe,(FeCN6)3  + 
6K,SO,. 

It  is  also  made  on  a  large  scale  by  precipitating 
ferrous  sulfate  with  potassium  ferrocyanid  and  ex- 
posing the  bluish  precipitate  to  the  air  till  it  oxidizes 
and  acquires  color  of  proper  depth. 

POTASSIUM  CYANID  (potassii  cyanidum  U.  S.P.). 
Tw^o  varieties  of  this  salt  are  known  in  commerce— 
(i)  the  commercial  cyanid,  which  is  used  for  photo- 
graphic purposes,  and  made  by  fusing  dried  potas- 
sium ferrocyanid  with  potassium  carbonate,  decanting 
the  semiliquid  mass  from  the  sediment  of  iron  and 
allowing  it  to  cool  and  solidify.  The  potassium 
cyanate,  which  is  a  by-product  in  this  reaction,  is 
dissolved  out  with  carbon  disulhd. 

The  second  method  for  the  production  of  (2)  pure 
potassium  cyanid  is  by  neutralizing  hydrocyanic 
acid  with  potassium  hydroxid.  This  is  most  con- 
veniently done  by  passing  HCN  gas  into  an  alcoholic 
solution  of  potassium  hydroxid: 

ist  method:  2K,Fe(CN)6  +  2K2CO3  =  loKCN-f- 
2KCNO  +  Fe..  +  2  CO.,. 


314  PHARMACEUTIC    CHEMISTRY. 

2d  method:  HCN  +   KOH  =   KCN  +  H,(). 

Potassium  cyanid  occurs  in  white,  opaque,  amor- 
phous pieces  or  granular  powder;  odorless  when  dry, 
deliquescent  in  air,  emitting  the  odor  of  HCN.  It  is 
soluble  in  2  parts  of  water,  sparingly  in  alcohol.  It 
should  be  90%  pure;  is  strongly  alkalin,  usually  con- 
taining 10%  of  a  carbonate.  It  is  used  in  the  arts  as 
a  solvent  in  the  manufacture  of  polishing  agents; 
in  the  electroplating  industries,  also  for  the  extraction 
of  gold  and  silver  from  the  rocks  with  which  it  forms 
soluble  compounds.     It  is  a  strong  poison. 

SILVER  CYANID  (argenti  cyanidum  U.  S.  P.), 
AgCN,  is  prepared  by  precipitating  silver  nitrate 
with  potassium  cyanid;  thus: 

AgNOg  -fKCN  =  AgCN  +  KNO3. 
The  salt  should  be  99.9%  pure,  which  corresponds  to 
80.48%  of  metallic  silver.  It  is  a  white,  odorless  and 
tasteless  powder,  permanent,  but  gradually  turning 
brown,  and  should  be  preserved  in  the  dark.  It  is 
insoluble  in  water,  alcohol  or  cold  nitric  acid,  but 
souble  in  boiling  nitric  acid,  evolving  HCN.  It  is 
also  soluble  in  ammonia  water,  potassium  cyauid  and 
sodium  th  osulfate  solution.  The  only  use  made  of 
the  salt  is  for  the  extemporaneous  preparation  of  the 
official  dilute  hydrocyanic  acid,  which  is  done  by 
mixing  silver  cyanid,  6  parts,  witli  mixture  of 
hydrochloric  acid,  5,  and  water,  55  parts,  agitating 
until  all  of  the  silver  chlorid  precipitates  and  pouring 
off  the  solution  of  HCN.  The  reaction  is  as  follows: 
AgCN  +  HCl  =  HCN  +  AgCl. 

AMMONIUM  SULFOCYANID,   NH.C^NS,  ammo- 


POTASSIUM    SUI.FOCYANID  315 

nium    thiocyanate,    is    made    by  dissolving  carbon 
disulfid  in  alcohol  and  heating  in  the  presence  of 
ammonia,  according  to  the  following  reaction: 
CS,  +   2NH3    =   NH.CNS  +  H^S. 
This  salt  is  very  analogous  to  the  following: 
POTASSIUM  SULFOCYANID,   KCNS,  potassium 
thiocyanate.     This  salt  may  be  prepared  by  fusing 
together  potassium  ferrocyanid  and  sulfur: 
K,Fe(CN)«  +  3S,  =  4K(CN)S_+  Fe(CNS)2. 

potassium 
sulfocyanid 

The  fused  mass  is  next  boiled  with  a  solution  of 
potassium  carbonate  which  converts  the  ferrous 
sulfocyanid  into  potassium  sulfocyanid  and  ferrous 
carbonate,  which  latter  precipitates: 

Fe(CNS)2  +   K2CO3  =   2K(CN)S    +    FeCOg. 

The  soluble  sulfocyanids  can  be  prepared  by 
direct  union  of  the  soluble  cyanids  with  sulfur,  as 
follows: 

NH.CN  +  S  =  NH.CNS. 

Potassium  sulfocyanid  is  present  in  minute  quanti- 
ties in  the  human  saliva. 

Tests. — With  ferric  chlorid,  the  sulfocyanids 
give  a  blood-red  coloration,  which  is  not  discharged 
by  strong  hydrochloric  acid,  thus  distinguishing  it 
from  the  red  ferric  acetate. 

POTASSIUM  CYANATE,  KCNO.     This  may^be 
prepared  by  exposing  fused  potassium  carbonate  Tor 
some  time  to  the  air;  the  salt  absorbs  oxygen  from 
the  air  and  is  converted  into  the  cyanate: 
2KCN    +    O,    =    2KCNO. 


3l6  PlIAKMACiaTlC    Clll^MISTRV. 

The  salt  can  also  be  prejjared  by  adding  lead  oxid 
to  fused  putassium  cyanid;  the  potassium  salt  unites 
with  the  oxygen  of  the  lead,  forming  the  cyanate  and 
setting  the  metal  free. 

AMMONIUM  CYANATE,  NH.CNO,  a  very  soluble 
salt,  which  can  be  prepared  by  mixing  a  solution  of 
potassium  cyanate  and  ammonium  sulfate.  A 
double  decomposition  takes  place,  forming  potassium 
sulfate  in  addition  to  the  ammonium  salt.  This,  upon 
the  addition  of  alcohol,  precipitates  the  potassium 
sulfate,  leaving  the  ammonium  cyanate  in  solution: 

2KCNO  +  (NHJ2SO,  =  2NH,CNO  +  K2SO,. 

This  salt  is  very  interesting  chemically,  because  it 
is  isomeric  with  urea,  CO(NH2)2.  Urea  can  be 
prepared  from  ammonium  cyanate  by  simply  evapo- 
rating its  solution  to  dryness  on  the  water-bath.  It 
is  evident,  therefore,  that  boiling  water  is  sufficient  to 
rearrange  the  atoms  in  the  molecule;  on  the  other 
hand,  urea  may  be  reconverted  into  ammonium 
cyanate  by  heating  it  to  dull  redness.  When  this  is 
done,  cvanuric  acid  forms  and  ammonia  gas  is  given 
off: 

3CO(NH,,),    =    H3C3N3O3    +    3NH3. 

cyanuric  acid 

If  cyanuric  acid  is  heated  more  strongly,  it  splits 
into  cyanic  acid,  which  distills  over: 
H.,(;,N3()3  =   3HCNO. 

cyanic  aciii 

If,  now,  the  cyanic  acid  be  neutralized  with  the 
ammonia  previously  evolved,  ammonium  cyanate  is 
reproduced. 


THE    ETHERS. 


317 


Other  organic  compounds  of   nitrogen  tvill  be  dis- 
cussed in  a  special  chapter. 


THE  ETHERS. 

(R-O— K) 


Molecular 

Boiling- 

Specific 

formula 

point 

gravity 

Dimethyl  ether 

CaHftO 

23.6° 

Diethyl  ether      

C4HI00 

K-6° 

o"73i     (  4°) 

Dipropyl  ether              .  . 

C6HI40 

go. 7° 

0-763     (  0°) 

Di-isopropyl  ether 

C6HX40 

69° 

0-743     (  0°) 

Di-normal-butyl  ether..  . 

CsH.sO 

141° 

0-784     (  0°) 

D''-secondary-butyl  ether 

CsHisO 

121° 

0-756    (21=) 

Di-isobutyl  ether 

CsHxsO 

122° 

0-762     (15°) 

Di-isoamyl  ether 

CoH^.O 

170° 

0-799     (  0°) 

Di-normal-ortyl  ether.  .  . 

C,6H340 

280° 

Melting- 
point 

0-805     (17°) 

Dicetyl  ether 

C,.H660 

55° 

As  has  been  shown,  alcohols  correspond  to  the 
inorganic  alkali  hydroxids.  Similarly,  it  may  be 
stated  that  ethers  correspond  to  metallic  oxids. 

The  ethers  are  formed  by  replacing  the  hydrogen 
of  the  hydroxyl  of  an  alcohol  -with  an  alkyl.  The 
compound  ethers  may  be  formed  by  a  similar  intro- 
duction of  an  acid  radical  or  by  replacing  the  hydro- 
gen of  the  carboxyl  of  an  acid  with  an  alkyl.  Mixed 
ethers,  on  the  other  hand,  are  oxids  of  two  different 
alkyls;  thus: 

Simple  ether  is  ethyl  oxid,  CjH^ — O — CjH^. 

Compound  ether  (or  ester)  may  be  represented  by 
ethyl  acetate,  CH3COOCH,,. 


310  I'HARMACELiTIC    CHEMISTRY. 

Mixed  ether  may  he  represented  by  methyl-ethvl 
ether,  CH3OC2H5. 

Preparation. — (i)  Simple  ethers.  These  may  be 
prepared  by  treating  an  alcohol  with  an  alkali  metal 
and  the  resulting  compound  with  their  halogen 
derivative  of  a  hydrocarbon.  Thus,  methyl  ether 
may  be  prepared  as  follows: 

(i)   CH3OH  +  K  =  CH3OK  +  H. 

potassium 
ethylate 

(2)   CH3OK  +   CH3CI   =   (CH3),0   +   KCl. 

Ethyl  ether,  "sulfuric  ether,"  ethyl  oxid,  is  the 
ordinary  ether  (aether  U.  S.  P.).  This  is  the  common 
ether  as  we  know  it.  It  can  be  formed  when  sodium 
ethylate  is  warmed  with  ethyl  halid.  This  is  the 
"synthesis  of  Williamson,"  which  not  only  indicates 
the  formation  of  ether,  but  also  its  structure: 

C2H30Na  +  QHJ  =  C2H5— O— CoHs  +  Nal. 

Ethyl  ether  is  prepared  on  a  large  scale  by  heating 
alcolol  with  dehydrating  agents,  such  as  sulfuric 
acid;  thus,  if  we  abstract  from  two  molecules  of 
alcohol  one  molecule  of  water,  ether  rfesults,  accord- 
ing to  the  following  ecjuation: 

2C2H5OH  =  C2H5OC2H5  +  H2O. 

It  can  be  prepared  by  heating  a  mixture  of  5  parts  of 
90%  alcohol  and  9  parts  of  concentrated  sulfuric 
acid  in  a  flask  provided  with  a  thermometer  and  a 
dropping  funnel  and  connected  with  a  condenser. 
When  the  tciupcrature  rises  to  140°,  the  mi.xture  will 


CONTINUOUS    ETHER    PROCESS.  319 

begin  to  boil  and  ether  distills  over.  Alcohol  is  now 
slowly  run  in  from  the  dropping  funnel,  the  tempera- 
ture at  the  same  time  being  carefully  regulated 
to  140-145°,  until  a  considerable  quantity  of  the 
ether  passes  over.  The  liquid  in  the  receiver  may  be 
said  to  be  a  crude  mixture  of  ether,  alcohol  and  water, 
and  in  addition  it  contains  sulfur  dioxid  which  is 
produced  by  the  decomposition  of  the  acid.  This 
is  shaken  with  dilute  soda  in  a  separatory  funnel, 
the  layer  of  ether  which  floats  on  the  surface  is 
carefully  separated  and  distilled  from  quicklime  and 
purified  by  redistilling  from  a  water-bath.  The 
ether  so  prepared  is  about  90%  pure  and  contains 
traces  of  alcohol  and  water.  These  are  removed  by 
adding  pieces  of  bright  metallic  sodium,  allowing  to 
stand  for  several  hours  and  again  distilling.  Sodium 
ethylate  and  hydroxid  remain  behind  and  pure  ether 
passes  over.  The  ether,  in  order  to  answer  the  re- 
quirements of  the  Pharmacopoeia,  must  be  at  least 
96%  pure.  The  reaction  described  above  is  known 
as  the  "continuous  ether  process";  that  is  to  say, 
with  a  given  quantity  of  ether  which  serves  there  as 
a  dehydrating  agent  only,  unlimited  quantities  of 
ether  should  be  prepared.  As  a  matter  of  fact,  a 
comparatively  small  quantity  of  the  acid  transforms 
a  very  large  quantity  of  the  alcohol,  but  the  process 
has  a  limit  in  that  the  acid  finally  becomes  diluted 
with  the  abstracted  water  and  a  part  of  it  is  reduced 
with  the  formation  of  sulfur  dioxid.  The  reaction 
really  takes  place  in  two  stages:  first,  the  alcohol  is 
converted    into    ethyl    hydrogen    sulfate    (sulfovinic 


320  PHARMACEUTIC    CHEMISTRY. 

acid),  this  compound  next  interacts  with  alcohol, 
yielding   ether   and   sulfuric   acid;   thus: 

(i)   QHjOH  +  H,SO,  =  QHs  — HSO,  4-  H,0. 

ethyl  hydrogen 
sulfate. 

(2)  (UIjHSOj  +  QH.OH  =  QH,— O— C.H.  + 
H.,S(),. 

Properties. — Eth_\l  ether,  misnamed  "sulfuric 
ether,"  because  sulfuric  acid  is  used  in  its  manufac- 
ture, is  a  colorless,  very  volatile  and  highly  inflam- 
mable liquid,  having  a  specific  gravity  of  0.726,  a 
boiling-point  of  35°,  and  containing  not  more 
than  4%  of  alcohol.  With  air  it  forms  a  highly 
exy)losive  mixture: 

C.HjoO  -(-  6O2  =  4CO,  +  sH.O. 

ether 

Its  vapor  is  heavier  than  air,  and  its  administration 
by  artificial  light  is  only  permissible  when  the  source 
of  the  latter  is  high  above  the  source  of  the  ether. 
Under  no  circumstances  should  ether  be  evaporated 
over  an  open  flame.  It  is  soluble  in  about  ten  parts 
of  water  and  in  all  ])roportions  in  alcojiol  and  other 
organic  solvents;  it  is  also  a  good  solvent,  especially 
for  all  the  organic  acids  (distinction  from  inorganic 
acids).  It  is  employed  in  considerable  quantities 
in  surgery,  principally  because  when  inhaled  it  first 
produces  intoxication  and  then  anesthesia.  In  this 
respect  it  is  similar  to  chloroform  in  that  it  causes 
insensibility.  In  pharmacy  it  is  used  as  a  solvent  for 
resins,    fats,   oils,   alkaloids,    for   the   preparation  of 


PROPERTIES    OF    THE    ETHERS.  32 1 

collodions  and  the  32.5%  spirit  (spiritus  setheiis 
U.  S.  P.);  this,  with  2.5%  of  ethereal  oil,  constitutes 
Hoffmann's  anodyne  (spiritus  aetheris  compositus 
U.  S.  P.) 

(2)  Mixed  £///en.— METHYL-ETHYL  ETHER, 
CH3— O— C2H5,  is  prepared  by  distilling  methyl 
alcohol  with  ethyl  sulfuric  acid.  It  is  sometimes 
used  as  an  anesthetic. 

PROPERTIES  OF  THE  ETHERS.— The  ethers 
and  esters  of  the  lower  members  of  the  monatomic 
alcohols  and  of  the  fatty  acids  possess  some  general 
characteristics:  they  all  have  a  pleasant  odor,  usually 
resembling  that  of  some  fruit,  and  mixtures  of  these 
have  been  used  in  the  manufacture  of  synthetic 
fruit  essences,  or  fruit  ethers,  sometimes  called  "fruit 
oils."  Thus,  artificial  pineapple  essence  consists  of 
chloroform,  i  part;  aldehyd,  i  part;  ethyl  butyrate,  5 
parts;  amyl  butyrate,  10  parts;  with  glycerin,  3  parts. 
Straivherry  essence  consists  of  ethyl  nitrate,  i  part; 
ethyl  acetate,  5  parts;  ethyl  formate,  i  part;  ethyl 
butyrate  5  parts;  methyl  salicylate,  i  part;  amyl 
acetate,  3  parts;  amyl  butyrate,  2  parts;  with  glycerin, 
2  parts.  Pear  essence  consists  of  ethyl  acetate,  5 
parts;  amyl  acetate,  10  parts;  benzoic  acid,  i  part; 
with  glycerin,  10  parts.  Apple  essence  is  an  alco- 
holic solution  of  amyl  valerate.  The  ethers  given 
under  the  first  three  headings  above,  and  in  the 
quantities  given  therein,  should  be  dissolved  in  a 
sufficient  quantity  of  pure  alcohol  to  make  120  parts 
bv  measure.  These  mixtures  are  very  powerful  and 
very  small  quantities  go  a  long  way  in  producing  the 


322  PHARMACEUTIC   CHEMISTRY. 

flavors.  When  ingested  in  larger  quantities  they 
are  deleterious.  There  are  many  other  fruit  essences 
or  mixtures  of  ethers  which  are  extensively  employed 
to  imitate  whiskies,  brandies,  rums  or  wines,  and 
some  of  them  added  in  small  quantities  to  young 
wines  improve  their  "bouquet,"  which,  ordinarih',  is 
only  produced  in  these  by  aging.  On  the  other  hand, 
the  esters  of  the  higher  acids  constitute  the  fixed  oils 
and  fats.  All  the  esters  of  the  monatomic  alcohols 
and  monobasic  acids  are  neutral  compounds,  the 
lower  members  being  volatile  liquids,  while  the  higher 
members  are  usually  nonvolatile  solids.  The  com- 
binations with  polyatomic  alcohols  and  polybasic 
acids  give  rise  to  the  neutral,  acid  or  basic  com- 
pound esters,  closely  analogous  to  the  inorganic 
neutral,  acid  or  basic  salts.  They  sometimes  give 
rise  to  compounds  like  glycerophosphoric  acid, 
C3H5(OH)2H2P04,  which  in  the  same  molecule 
affords  the  characteristics  of  all  these  varieties  of 
compounds.  The  chief  difference,  chemically,  be- 
tween the  ethers  and  the  esters  is  in  the  fact  that 
the  ethers  are  not  acted  upon  by  alkali  hydroxids, 
while  the  esters  are  decomposed,  forming  an  alcohol 
and  a  salt  of  the  alkali  metal  (soap). 

Saponification,  as  has  been  stated  under  Fats,  is  the 
term  applied  to  a  process  resembling  the  action  of 
alkali  hydroxids  upon  the  fats  with  the  production  of 
soap  and  glycerin.  The  same  may  be  said  that  when 
an  ester,  such  as  ethyl  acetate,  is  boiled  with  an  alkali 
hydroxid,  a  salt  (alkali  acetate)  and  an  alcohol 
(ethyl  alcohol)  are  formed.     This  method  is  employed 


THE    ESTERS.  323 

not  only  for  the  identification  of  the  esters,  but  also 

for  the  quantitative  determination  of  their  strength: 

CH3COOC2H,  +  KOH  =  CH^COOK  +  C.H,.OH 

ethyl-acetic  acid  ester        +    alkali     =  alkali  acetate      +      ethyl 

alcohol. 

Among  the  esters  of  the  aliphatic  series,  ethyl 
acetate,  methyl  salicylate,  ethyl  nitrite,  ethyl  sulfate, 
amyl  nitrite  and  ethyl  carbamate  may  be  mentioned. 

(3)  Esters.— ETHYL  ACETATE,  acetic  ether, 
acetic  acid,  ethyl-ester  (aether  aceticus  U.  S.  P.), 
CH3COOC2H5.  It  is  prepared  by  distilling  a  mix- 
ture of  sodium  acetate  and  alcohol  with  sulfuric 
acid: 

C2H5OH  -f  NaC^HjO,  +  H2SO,  =  CH3COOC2H5 
+  H2O  +  NaHSO,. 

The  distillate  is  washed  with  a  solution  of  calcium 
chlorid,  to  free  it  from  the  water,  then  with  milk  of 
lime  to  free  it  from  sulfuric  acid.  It  is  next  decanted 
dried  over  calcium  chlorid  and  finally  redistilled. 
Acetic  ether  is  an  inflammable,  colorless,  limpid 
liquid,  boiling  at  76°,  and  having  a  specific  gravity  of 
0.885.  It  possesses  a  pleasant,  fruity  odor,  not  un- 
like that  of  apples,  hence  it  has  gained  the  name  of 
"apple  oil."  It  is  soluble  in  about  8  parts  of  water, 
which  becomes  slightly  acid  from  its  decomposition 
into  acetic  acid  and  alcohol  (hydrolysis) .  It  is  soluble 
in  alcohol  and  all  the  other  organic  solvents,  and 
serves  as  a  good  solvent  for  the  essential  oils,  resins, 
nitrocellulose  and  morphin.  Small  quantities  of  it 
added  to  hock  wine  and  to  eau  de  cologne  improve 
their  odor. 

ETHYL  NITRITE,  nitrous  ether,  CH^— O— NO, 


324  PHARMACEUTIC    CHEMISTRY. 

is  a  fragrant,  ethereal  mobile  liquid,  with  a  boiling- 
point  of  16.5°  and  a  specific  gravity  of  0.947.  It  is 
insoluble  in  water,  but  freely  soluble  in  alcohol  and 
other  organic  solvents.  It  is  made  by  decomposing 
sodium  nitrite  with  sulfuric  acid  in  presence  of  ethyl 
alcohol,  according  to  the  following  reaction: 

2C2H5OH  +  2NaN02  +  H2SO,  =  2C2H5NO,+ 
2H2O  +  Na^SO,. 

This  ether  is  official  in  the  spirit  of  nitrous  ether, 
sometimes  called  "sweet  spirit  of  nitre";  spiritus 
aetheris  dulcis  (spiritus  a^theris  nitrosi  U.  S.  P.). 
The  spirit  is  an  alcoholic  solution  containing  about 
4%  of  the  ester;  when  assayed,  this  spirit  should 
yield  eleven  times  its  own  volume  of  nitric  oxid  (NO). 
The  spirit  is  made  by  decomposing  the  sodium  nitrite 
with  the  acid  in  presence  of  alcohol,  as  stated 
above,  washing  it  with  ice-water  in  which  the  pota- 
sium  sulfate  is  but  sparingly  soluble,  adding  a  solu- 
tion of  sodium  carbonate  to  neutralize  the  sulfuric 
acid,  separating  the  ether,  drying  it  with  potas- 
sium carbonate  and  filtering  it  into  22  times  its  own 
weight  of  alcohol.  The  spirit  is  used  as  a  diaphoretic 
and  diuretic.  It  is  incompatible  with  many  common 
chemicals  and  drugs,  chief  of  which  are  antipyrin, 
sodium  salicylate,  potassium  iodid,  fluid  extract  of 
buchu  and  the  (annates. 

METHYL  SALICYLATE,  "artificial  oil  of  winter- 
green,"  synthetic  oil  of  wintergreen,  CgH^ — OH — 
COOCH3.  Methyl  salicylate  is  a  colorless  liquid, 
])ossessing  a  strong  odor  and  taste  of  the  oil  of 
gaultheria,  which  latter  is  composed  almost  entirely 


ETHYL    SULFATE,  325 

of  the  above  ester.  It  is  also  identical  with  the  oil 
of  sweet  birch  (betula).  The  liquid  boils  at  220°, 
and  has  a  specific  gravity  of  1.183  to  1.185.  It  is 
slightly  soluble  in  water,  but  freely  soluble  in  alcohol 
and  the  organic  solvents.  It  is  made  by  heating 
together  methyl  alcohol,  salicylic  and  sulfuric  acids: 

CsH^.OH.COOH  +  CH30H  +  H2SO,  =  CeH,.OH. 
COO.CH3  +  H2O  +  H2SO,. 

The  ester  is  employed  as  a  flavoring  agent  and  as 
external  application  in  rheumatism. 

ETHYL  SULFATE,  heavy  oil  of  wine,  is  the  true 
sulfuric  ether,  CjHj— SO,— C2H5.  This  is  a  heavy 
yellow  oily  liquid,  prepared  by  mixing  equal  volumes 
of  alcohol  and  sulfuric  acid  and,  after  twenty-four 
hours,  subjecting  to  distillation  and  collecting  the 
portion  passing  between  150  and  160°  C. 
2C,H50H  +  H2SO,  =  C2H5— SO,  — C2H5  +  2H2O. 

When  mixed  with  an  equal  volume  of  ether,  it 
constitutes  the  official  ethereal  oil  (oleum  aethereum 
U.  S.  P.),  a  constituent  of  Hoffmann's  anodyne. 

ETHYL  CARBAMATE,  urethane,  ethvl  urethane, 
/NH3 
CO  (aethylis  carbamas  U.  S.  P.),  an  ester  of 

\OC3H, 
carbamic  acid  obtained  by  reacting  with  ethyl 
alcohol  upon  carbamid  (urea)  or  one  of  its  salts. 
It  occurs  in  colorless,  odorless  prisms,  melting 
between  50  and  51°  C,  and  soluble  in  i  part  water, 
0.6  part  alcohol  and  the  other  organic  solvents. 
Reaction : 

CO(NH,),HN03+C,H,OH  =  NH4N03+CONH,-0-C.H.; 
urea  nitrate  ethyl  carbamate. 


326  PHARMACEUTIC    CHE.MISTRY. 

The  salt  is  reputed  as  an  excellent  hypnotic,  free 
from  untoward  after-effects. 

AMYL  NITRITE  (amylis  nitris  U.  S.  P.),  C^H,!- 
ONO.  It  is  a  slightly  yellowish  liquid  possessing  the 
suffocating  odor  characteristic  of  the  amyl  com- 
pounds, a  boiling-point  of  96°  and  a  specific  gravity 
of  0.873.  It  is  prepared  by  the  action  of  nitrous  acid 
on  pentyl  alcohol.  The  liquid  is  distilled  and  puri- 
fied by  washing  and  rectification.  It  is  insoluble  in 
water,  but  miscible  with  all  of  the  organic  solvents. 
It  volatilizes  at  ordinary  temperatures,  and  can  best  he 
kept  in  hermetically  sealed  glass  bulbs  or  pearls  which 
can  be  crushed  in  a  handkerchief  for  inhalation.  It 
is  used  as  a  heart  tonic.  The  liquid  should  be  com- 
posed of  at  least  80%  of  amyl  nitrite,  chiefly  the  iso- 
amyl,  0.26  grams  of  which,  when  assayed  by  the 
official  process,  should  yield  about  40  c.c.  of  gas. 

SALACETOL,  salantol,  acetol  salicylate,  CgH^- 
.(OH)CO— OCH2— COCH3.  It  is  prepared  by  the 
interaction  between  monochlor-acetone  and  sodium 
salicylate.  The  salt  was  introduced  as  a  substitute 
for  salol.  It  occurs  in  fine,  needle-shaped  crystals, 
melting  at  71°;  insoluble  in  water  and  cold  alcohol, 
but  freely  soluble  in  hot  alcohol  and  the  other  organic 
solvents. 

Other  ethers  of  importance,  such  as  ethyl  and 
methyl  benzoate,  butyrate,  valerate  and  nitrate,  are  all 
prepared  by  a  process  similar  to  the  one  given  under 
Ethvl  Acetate. 


CHAPTER  XXVII. 
THE  ALDEHYDS. 

/,0 


(CnH2,0)=R— C^ 


H 


Name 


Formula 


iBoiling- 
I    point 


Formaldchyd H.CHO 

Acetaldehyd CH3.CHO  2r 

Propionaldehyd C.Hs.CHO  49' 

Butvraldehyd C3H7.CHO  74° 

Isobutvraldehyd •  .  C3H7.CHO  63° 

Valeraldehyd  '. i  C4H9.CHO  ;   102° 

Isovaleraldehvd C4H9.CHO  92° 

Caoronaldehv-d C.H„.CHO  ,   128° 

Heptaldehyd'or  ((Enanthol) C6H,,.CHO  155° 

The  examination  of  the  above  list  of  aldehyds  and 
the  general  formula  for  the  same  will  show  that  they 
are  alcohols  minus  two  hydrogen  atoms.  The  name 
aldehyd  was  derived  from  dehydrogenized  alcohol 
(a/cohol  (^e/i^irogenatus) .  They  are  obtained  by  the 
oxidation  of  the  primary  alcohols.  The  lowest  mem- 
ber of  the  series  is  obtained  by  the  oxidation  of  the 
lowest  alcohol,  namely,  methyl  alcohol.  This  aldehyd 
has  sometimes  been  named  methaldehyd,  but  at  the 
present  time  the  nomenclature  of  the  aldehyds  is 
obtained  from  the  acids  they  form  upon  oxidation. 
Thus,  the  aldehyd  of  methyl  alcohol,  upon  oxidation, 
327 


328  PHARMACEUTIC    CHEMISTRY. 

yields  formic  acid,  and  has,  therefore,  been  named 
form-aldehyd.  The  aldehyd  of  ethyl  alcohol  upon 
oxidation  yields  acetic  acid  and  has  accordingly 
been  named  acet-aldehyd.  The  aldehyd  of  the  third 
alcohol  yields  proprionic  acid  and,  correspondingly, 
has  been  called  proprion-aldehyd. 

Preparation. — When  the  primary  alcohols  arc 
mildly  oxidized,  two  hydrogens  are  removed,  split- 
ting off  water,  and  aldehyd  is  formed.  By  further 
oxidation,  aldehyd  takes  up  oxygen  and  becomes 
an  acid.  Aldehyds  are,  therefore,  the  intermediate 
products  between  the  alcohols  and  acids;  thus: 

C.H.O     .     C,H,()     .     C.H.O, 

alcohol  aldehyd  acetic  acid 

Properties. — The  characteristic  property  if  all 
aldehyds  is  their  i)ower  to  combine  directlv  with 
ammonia,  hydrocyanic  acid,  the  alkalin  sulfites  and 
many  other  substances.  They  are  strong  reducing 
agents.  Thus,  when  aldehyd  is  added  to  a  solution 
of  silver  nitrate,  rendered  alkalin  with  ammonia 
water,  the  solution  is  reduced,  and  metallic  silver  is 
deposited  on  the  walls,  forming  a^  mirror.  By 
oxidation  aldehyds  are  converted  into  acids,  and  by  a 
process  of  reduction  they  are  reconverted  into  alco- 
hols. The  structure  of  the  aldehyds  may  be  proven 
by  the  action  of  phosphorus  pentachlorid  upon  them, 
I)roducing  a  dihalid  derivative  and  splitting  oft"  i)hos- 
])h()ric  oxychlorid,  as  follows: 

C.,H,()  +  PC1,    =   C.,H,,Cl,    -f    VOi\ 

ethylidene 
chlorid. 


ALDEHVD  AND  KETONE  GROUPS.       329 

It  will  be  seen  from  the  above  that  an  atom  of 
divalent  oxygen  was  replaced  by  two  monovalent 
chlorins,  indicating  the  presence  of  the  characteristic 
radical  carhonyl,  a  carbon  atom  in  combination  with 
oxygen  (C  =  0)  and  the  absence  of  the  hydroxyl 
( — OH)  group.  These  peculiar  properties  of  the 
aldehyds    presuppose    the    presence    of    the   group 

/H 

— C{        ,  called  the  aldehvd  group. 
^O 

When  ketones  are  treated  similarly  to  aldehyds 
with  phosphorus  pentachlorid,  a  similar  dihalid  sub- 
stitution product  is  formed,  and  phosphoric  oxy- 
chlorid  is  s])lit  off;  thus: 

CaH.O    +   PCI,-,    =      C3H,C1,      +     POCI3 

acetone  dichlorpropane 

This  reaction  shows  that  the  :=C=0  group  must 
exist  in  both  classes  of  compounds  and,  indeed,  this 
latter  group  is  characteristic  of  all  the  ketones. 

Whereas  the  aldehyds  are  produced  from  primary 
alcohols  alone,  the  carbonyl  (CO)  group  must  be 
present  at  the  end  of  a  carbon  chain;  thus: 


H,0 


.p 

CH.OH    + 

methyl  alcohol 

0 

H.cf       + 

formaidehyd 

CH3 

CH3 

1 

_CH30H 

ethyl  alcohol 

+ 

0 

^H    -1 

acetaldehyd 

4-   H2O 


330  PHARMACEUTIC    CFIEMISTRY. 

In  the  ketones,  however,  the  carbonyl  group  must 

be  located  in  the  middle  of  a  carbon  chain;  thus: 

CH3  CH3 

I  1 

H3C— C— O— H    +   O    =    C  =  0    +   H.,0 

I  I 

H  CH, 

secondary  propyl  dimethyl 

alcohol  ketone 

Furthermore,  it  may  be  stated  that  aldehyds  can  be 
oxidized  without  breaking  the  carbon  chain,  whereas 
the  ketones  when  subjected  to  oxidation  lose  both 
carbon  and  hydrogen  in  the  process.  This  can  be 
illustrated  by  the  oxidation  of  acetaldehyd,  which 
produces  acetic  acid,  and  of  dimethyl  ketone  which 
decomposes  into  acetic  acid,  carbon  dioxid  and 
water. 

Aldehyds  and  ketones  pass  into  alcohols  on  reduc- 
tion. Thus,  acetaldehyd  forms  ethyl  alcohol,  while 
acetone  yields  secondary  propyl  alcohol.  With 
hydrocyanic  acid  an  additive  compound  is  formed, 
known  as  cyanhydrin,  of  the  aldehyd  or  ketone 
employed.  Thus,  aldehyd  gives  acetaldehyd  cyan- 
hydrin, CH3CH(OH)CN,  while  acetone  forms  ace- 
tone cyanhydrin,  CH3C(OH)(CN)CH3.  With  a 
saturated  solution  of  sodium  bisulfite,  addition  com- 
pounds known  as  bisulfite  compounds  of  the  re- 
spective aldehyd  or  ketone  are  formed;  thus: 

/OH 
^C=0    +   NaHSOs   =  =C( 

\S0..,Xa 

When  the  above  comijound  is  formed  with  acetal- 


ALDOXIMKS,    KETOXIMES,    ALDEHYD   AMMONIAS.       33 1 

dehyd,  it  is  known  as  acetaldehyd  sodium  bisulfite,  or 
"ethyl-oxy-sulfonate  of  sodium." 

When   aldehyds   and   ketones  are   reduced   with 
hydroxylamin  by  the  removal  of  oxygen,  oximes  are 
formed.     Thus,    when    aldehyds   are    treated    with 
hydroxylamin,  aldoximes  are  formed: 
CH3CHO   +  NH3OH   =  CH3CH  =  N0H  +  H,0. 

acetaldehyd        hydroxylamin  acetaldoxime 

With  ketones  a  similar  reaction  occurs,  giving  rise 
to  kdoxlmes,  thus: 

01^3— CO— CH3  +  NH3OH  =  (CHQ^CNOH  + 

acetone  hydroxylamin  acetoxime 

HjO. 

With     hydrazin     (NH2— NH2),     phenylhydrazin 
(NH— CgHj.NHa)     and     some    other    derivatives, 
aldehyds  and  ketones  combine  splitting  off  water, 
forming  hydrazones  and  phenylhydrazones  ;  thus: 
=  C  =  O  +  H^N— NH— C,H,  =  C  =  N— NH— C,H, 

^Ishenylhydrazine  phenylhydrazone 

+  H,0. 

In  the  case  of  acetaldehyd,  the  product  is  known  as 
acetaldehyd-phenylhydrazone, 

CH3— CH  =  N— NH— CgHj. 
With  ammonia,  aldehyds  form  aldehyd-ammonias; 
thus: 

.OH 
CH3— CHO    +   NH3    =  CH3— CH^ 


aldehyd  ammonia 

The  aldehyd  ammonias  are  soluble  in  water,  are 
decomposed   by  acids   with    the    formation    of   the 


332  PHARMACEUTIC    CHEMISTRY. 

ammonium  salt  of  the  acid  and  the  regeneration  of 
the  aldehyds.  The  only  aldehyd  which  behaves 
differently  is  formic  aldehyd  which  gives,  with  am- 
monia, hexamethylenetetramin;  thus: 

6HCH()    +    4NH3    =    (CH^)eN,    +    6H.,Q 

formaldehya  hexamethylenetetramin 

The  above  reaction  is  made  use  of  in  the  deter- 
mination of  the  strength  of  formaldehyd  solutions. 
The  caustic  alkaUs  have  different  effects  upon  the 
aldehyds  from  ammonia.  They  resinify  the  lower 
members  of  the  series,  giving  rise  to  a  brown, 
resinous  substance  of  unknown  composition,  called 
aldehyd-resin. 

From  the  above  comparison  many  points  of 
similarity  between  the  aldehyds  and  ketones  can 
be  seen.  The  points  of  difference  between  them 
are  the  following:  (i)  Aldehyds  may  be  oxidized  to 
monobasic  acids  containing  the  same  number  of 
carbon  atoms,  while  the  ketones  (open  chain),  when 
oxidized,  yield  acids  containing  fewer  carbon  atoms, 
while  the  cyclic  ketones  form  dibasic  acids  of  the 
same  number  of  carbons.  (2)  Aldehyds  polymerize 
easily;  ketones  do  not.  (3)  Aldehyds  reduce  am- 
moniacal  solutions  of  silver  nitrate;  ketones  do  not. 
(4)  Aldehyds  redden  solutions  of  magenta  which 
have  been  decolorized  by  sulfur  dioxid;  ketones  do 
not.  (5)  The  aldehyds  of  the  aromatic  series  are 
converted  by  caustic  potash  into  a  salt  of  tlio  acid 
and  an  alcohol;  ketones  are  not. 

.Aldehyds  unite  with  the  alcohols  in  the  presence  of 


FORMALDKHVD.  ^2;^ 

a  little  hydrochloric-acid  gas,  forming  acetals.  Thus, 
formaldehyd  combines  with  methyl  alcohol,  giving 
methytal,  H^CXOCHj),.  Acetaldehyd  with  ethyl 
alcohol  yields  aceial,  CH3 — CH(OC2H5)2.  The 
equation  representing  the  reaction  is  as  follows: 


CH3CH 


H:  oaHj 

0+  =CH.,-CH(0C,H5),  +  H,0 

H:     OC,H,       ethylal  (ethylacetal) 


FORMALDEHYD,  methaldehyd,  formic  aldehyd, 
"formalin,"  HCHO,  is  obtained  by  the  oxidation  of 
methyl  alcohol  by  bringing  its  vapor  mixed  with  air 
in  contact  with  heated  platinum  or  copper.  It  may 
also  be  prepared  by  the  dry  distillation  of  calcium 
formate.  Formaldehyd  (Hofmann,  1867)  is  a  very 
pungent,  acrid  gas  which  condenses  to  a  liquid  at 
— 21  °.  The  pure  formaldehyd  is  very  unstable.  Its 
40%  water  solutions  are  used  extensively  as  antisep- 
tics. The  official  solution  (liquor  formaldehydi 
U.  S.  P.)  should  contain  not  less  than  37%  by  weight  of 
absolute  formaldehyd.  The  solution,  when  evapora- 
ted to  the  extent  of  6  to  10  ounces  to  every  1000  cubic 
feet  of  room,  according  to  Park,  forms  one  of  the 
most  reliable  disinfectants.  The  solution  polymer- 
izes very  rapidly,  forming  [)araformaldehyd,  para- 
form.  Paraform,  chemically,  is  trioxymethylene, 
(C  1120)3.  It  is  prepared  by  slowly  evaporating  a 
solution  of  formaldehyd  in  methyl  alcohol,  when 
colorless  crystals  of  paraform  will  separate.  When 
heated,    paraform    splits    into    three    molecules    of 


334  PHARMACEUTIC    CHEMISTRY. 

formaldehyd.  It  is  a  powerful  agent  employed  for 
the  preparation  of  formaldehyd,  and  its  vapor  has 
the  advantage  of  not  injuring  the  color  of  tapestries 
and  fabrics  of  household  goods.  It  is  also  used  in 
bandaging. 

The  gas  may  be  conveniently  generated  from  an 
ordinary  alcohol  lamp  filled  with  methyl  alcohol  and 
the  projecting  wick  surrounded  with  some  platinum 
foil.  The  lamp  is  Hghted  for  a  minute,  then  ex- 
tinguished, when  the  platinum  will  continue  to  glow 
giving  off  formaldehyd.  Formaldehyd  is  a  strong 
antiseptic,  and  a  few  drops  will  preserve  a  consider- 
able quantity  of  material.  Thus,  half  a  grain  of 
formaldehyd  will  keep  a  quart  of  cow's  milk  sweet 
for  several  days.  In  technology  formaldehyd  has 
been  employed  for  rendering  gelatin  and  glue  in- 
soluble in  water,  also  as  a  substitute  for  tannin  in  the 
leather  industry.  Lately  it  has  been  employed  in  the 
production  of  artificial  silk  by  exposing  fine  threads 
of  glue  to  the  formaldehyd  vapor.  With  the  casein 
(pot-cheese)  of  cow's  milk  formaldehyd  forms  an 
insoluble  substance  w^hich,  when  treated  with  talcum 
or  heavy  sj)ar,  is  made  into  a  stone-like -material  under 
the  name  of  gallalith.  Recently  billiard-table  balls 
and  bowling-alley  balls,  as  well  as  jncture  frames, 
have  been  made  of  gallalith. 

When  a  solution  of  formaldehyd  is  mixed  with 
lime-water,  it  slowly  polymerizes  to  a  sweet  syrup 
which,  upon  evaporation,  gives  a  compound  having 
the  formula  (CH._.0)b.  This  substance  is  known  as 
jormose  and  exhibits  many  properties  indicating  a  close 


ALDEHYD   AND    PARALDEHYD.  335 

relationship  with  grape-sugar.  The  above  fact  is 
very  interesting,  as  it  is  supposed  to  have  a  bearing 
upon  the  production  of  sugar  by  plants.  It  is  known 
that  plants  absorb  carbon  dioxid,  and  it  is  thought  that 
during  the  assimilation  of  carbon  dioxid  by  the  green 
coloring  matter  (chlorophyl)  in  the  presence  of  the 
sun's  rays,  it  is  converted,  first,  into  formaldehyd 
which,  by  a  process  of  polymerization,  is  converted 
into  sugar. 

ALDEHYD.— This  name  is  commonly  given  to 
acetaldehyd,  ethaldehyd,  CH3CHO.  It  is  prepared 
by  oxidation  of  ethyl  alcohol  with  a  solution  of  potas- 
sium dichromate  in  sulfuric  acid: 

3aH50H  +  KXr,0,+4H3SO=3CH3CHO  +Cr, 

(504)3  -fKoSO^    +7H2O.  acetaldehyd 

It  may  also  be  produced  by  heating  aldehyd 
ammonia  with  sulfuric  acid;  thus: 

CH3— CH        +  H,SO,  =  CH3— CHQ  +  NH.HSO, 

N^  aldehyd 

OH 

aldehyd  ammonia 

Aldehyd  is  a  colorless,  pungent  liquid,  readily 
soluble  in  water  and  boiling  at  2 1  °  C.  It  polymerizes 
readily,  giving  rise  to  paraldehyd. 

PARALDEHYD  is  a  colorless  liquid,  boiling  at 
124°  C.  and  having  the  formula  (CH3CHO)3.  It  is 
not  an  aldehyd,  chemically,  for  it  does  not  combine 
with  either  ammonia,  sodium  bisulfite,  nor  does  it 


336  PHARMACEUTIC    CHEMISTRY. 

reduce  ammoniacal  silver  nitrate.     It  is  prepared  by 

adding  a  few  drops  of  concentrated  sulfuric  acid  to 

aldehyd.     The  liquid  l)ecomes  hot,  and  when  cooled 

to  0°  C.  solidities,  forming  crystals  of  paraldehyd, 

which  liquefy  at  1 1  °  C.     Paraldehyd  (paraldehydum 

U.  S.  P.)  is  soluble  in  water,  and  is  one  of  the  official 

hypnotics. 

The  structure  is  as  follows: 

CH3 

i 
CH 


HaCHCX/CH.CH., 
O 

Acetaldehyd  undergoes  another  polymerization 
in  presence  of  potassium  carbonate.  It  condenses 
to  hydroxybutaldehyd,  commonly  known    as    ahiol 

CH3CHO  +  CH3CHO  =  CH-CH(OH)  —  CHXUH 

aldol 

Aldol  is  a  svru{)y  litjuid,  and  the  process  is  known 
as  ''aldol  condensation." 

TRICHLORALDEHYD,  chloral,  CCI3CHO.  Chlo- 
ral is  prepared  by  the  prolonged  action  of  chlorin 
upon  absolute  alcohol.  It  may  be  said,  chemically, 
to  be  a  substitution  of  acetaldehyd,  although  it  can- 
not be  obtained  from  it  by  the  direct  action  of 
chlorin.  The  usual  method  of  its  production 
(Liebig,  1832),  is  by  passing  dry  chlorin  gas  into 
alcohol.  The  reaction  which  takes  ])lace  is  a  com- 
plicated one,  giving  several  by-products.     Of  these. 


PREPARATION  AND  PROPERTIES  OF  CHLORAL.  337 

the  principal  one  is  a  compound  of  chloral  and 
alcohol,  known  as  chloral-ale oholate,  and  having  the 
formula  CCI3— CH(OH)— OCjH^.  This  compound 
bears  a  relation  to  the  acetals. 

Preparation. — When  a  slow  current  of  chlorin  is 
passed  through  cooled  ethyl  alcohol,  the  latter  is 
converted  into  aldehyd: 

(i)   CH3CH2OH  +  CI2  =  CH3CHO  +  2HCI. 

The  liquid  is  next  heated  and  the  current  of  chlorin 
is  continued  until  saturation.  The  chlorin  acts 
upon  the  aldehyd,  abstracting  three-fourths  of  the 
hydrogen  (united  with  the  carbon),  replacing  it  by 
chlorin,  and  thus  producing  chloral. 

(2)   CH3CHO   +  3CI2   =   CCI3CHO   +  3HCI. 

Description  and  Properties. — Chloral  is  an  oih', 
heavy  liquid  with  a  pungent,  irritating  odor  and  a 
boiling-point  of  98.  It  polymerizes  like  acetaldehyd 
on  keeping  or  in  the  presence  of  small  quantities  of 
mineral  acids.  Upon  addition  of  one-fifth  of  its  bulk 
of  water  and  shaking,  the  mixture  solidifies  with  the 
evolution  of  considerable  heat.  The  solid  crystal- 
line substance  is  known  as  chloral  hydrate  (chloral 
hydratum  U.  S.  P.),  or  hydrated  chloral,  having  the 
formula : 

CCI3CHO  +  H,0  =  CCl3CH(OH)3 

chloral  hydrate 

The  hydrated  chloral  has  a  very  faint  odor  of  the 
liquid  chloral  attached  to  it.  It  is  largely  used  in 
medicine  as  a  hypnotic,  and  it  has  been  stated  that  by 
the  sodium  carbonate  of  the  blood  it  is  decomposed 


338  PHARMACEUTIC    CHEMISTRY. 

into  chloroform,  though  this  statement  is  doubted 
by  some.  Chloral  hydrate  is  decomposed- by  caustic 
alkalis  and  alkalin  carbonates  into  chloroform  and 
a  formate  of  the  alkali  metal.  It  is,  therefore, 
incompatible  with  the  alkalis  and  they  should  never 
be  dispensed  together. 

2CCI3CHO  +    Ca(OH),=   2CHa3+    Ca(CH0,)2 

trichlor-  chloroform  calcium 

aldehyd  formate 

CCI3CHO   +   KOH   =  CHO^  +   KCHO2 

trichlor-  chloroform  potassium 

aldehyd  formate 

Similarly  to  aldehyd,  which,  with  nitric  acid,  is 
oxidized  to  acetic  acid,  chloral  or  trichloraldehyd  is 
oxidized  by  nitric  acid  to  trichloracetic  acid: 

(i)  2CH3CH()+  0,=  2CH3COOH 

acetic  acid. 

(2)  2CCI3CHO+  O,  =  2CCI3COOH     • 

trichloracetic 
acid. 

Trichloracetic  acid  (acidum  trichloraceticum 
U.  S.  P.)  is  a  monobasic,  organic  acid  having  the 
formula  CCI3COOH.  It  is  obtained  by  oxidizing 
chloral  hydrate  with  nitric  acid.  It  occurs  in  white, 
deliquescent  crystals  with  a  characteristic  odor,  it 
should  be  preserved  in  amber  glass  and  in  a  cool 
l)lace.  The  acid  is  very  soluble  in  all  solvents,  and 
when  heated  with  alkali  hydroxids,  it  decomposes  into 
chloroform  and  alkali  carbonate.  Chloral,  besides 
being  decomposed  by  the  alkali  hydroxids  and  car- 
bonates,   is  also   atTectcd   l)y   being   triturated    with 


CHLORAL-COMPOUNDS.  339 

camphor,  menthol,  thymol,  phenol  and  their  deriva- 
tives, with  which  it  Hquefies.  Chloral  hydrate  should 
with  water,  give  a  clear  solution  free  from  acid  and 
chlorin. 

BUTYL  CHLORAL,  CH3— CHCl— CCl.— CH- 
(OH)2,  is  obtained  by  passing  chlorin  into  acetal- 
dehyd,  and  has  properties  similar  to  chloral.  A 
hydrate  of  this  body,  hutyl  chloral  hydrate,  erroneously 
called  "croton  chloral  hydrate,"  has  been  used  in 
medicine  similarly  to  chloral.  It  corresponds  in 
constitution  with  ordinary  chloral  in  its  being  a 
butyl  aldehyd — C3H7CHO — from  a  molecule  of 
which  three  hydrogens  have  been  displaced  by  three 
chlorin  atoms.  Bromal,  CBrgCHO,  is  prepared  like 
chloral,  using  bromin  instead  of  chlorin.  lodal 
similarly  prepared  has  the  formula  CI3 — CHO. 

Besides  butyl-chloral  hydrate,  the  following  com- 
pounds have  been  used  as  choral  substitutes  in 
medicine: 

CHLORALAMID  (chloralformamidum  U.  S.  P. ),  a 
crystalline  body  made  by  direct  union  of  formamid 

OH 
with  choral,  CCl3CH<^  .       Melting-point, 

NH.CHO 

115°;  soluble  in  20  parts  water,  1.5  parts  alcohol. 

Chloralose,  anhydroglucochloral  (fr.  glucose  and 
chloral),  CgHn.ClgOe.  Melting-point,  185°;  soluble 
in  170  parts  water,  freely  in  alcohol. ' 

Hypnal,  monochloral  antypyrin  (fr.  antipyrin  and 
chloral),  a  crystalline  body  soluble  in  6  parts  water. 


340  PHARMACEUTIC    CHEMISTRY 

THE  KETONES. 

(R— CO— R) 


Name. 

Formula. 

Boiling- 
point. 

Acetone  or  dimethyl  ketone 

CH3.CO.CH, 

^6.° 

Propione  or  diethyl  ketone 

C2H5.CO.C.H5 

103- 

Butvrone  or  dipropyl  ketone 

C3H,.CO.C,H7 

144° 

Isobutyrone  or  di-isopropyl  ketone 

C3H7CO.C3H7 

:  ''^■: 

Isovalerone  or  di-isobutyl  ketone 

C4H9CO.C4H9 

i  187.° 

Caprone  or  diamyl  ketone 

C,Hx.CO.C5H„ 

227." 

Melting 
point 

OEnanthone  or  dihexyl  ketone.  .  .  . 

C6H,3CO.C6H.3 

305-° 

As  has  been  said  before,  ketones  resemble  aldehyds 
in  some  respects,  but  they  contain  the  group  =C0. 
The  simplest  of  the  ketones  or  acetones  is  the 
ordinary  dimethyl  ketone,  CH3 — CO — CH3,  or  ace- 
tone. 

ACETONE  is  prepared  by  subjecting  metallic 
acetates  to  dry  distillation;  thus: 

2NaC2H302  =  Na2C03  +  CH,— CO— CH3. 

Another  synthetical  reaction  which  also  demon- 
strates  its   structure    is   by    the   action   of   sodium 
methide  on  carbonvl  chlorid: 
/CI 
C-0-h2NaCH3  =  2NaCH-CH3-CO-CH, 

\ci 

Under  Aldehyds,  we  stated  that  all  primary  alcohols 
upon  o.xidation  form  first  the  corresponding  aldehyds 
which  pass  intP  the  fatty  acids  containing  the  same 
number  of  carbon  atoms;  thus: 

CH30H^-.     HCHO      —     HCOOH 

methyl  alcohol        formic  aldehyd.  formic  acid. 


ACETONE.  341 

The  secondary  alcohols  upon  oxidation  form 
ketones;  thus: 

CH3 
CH3CH3  I 

\/    ■       .       C  =  0+H,0 

CHOH  1 

CH3 
Acetone  is  prepared  on  a  commercial  scale  by 
subjecting   to   dry   distillation   the   ordinary    "gray 
lime"  obtained  as  a  by-product  in  the  manufacture 
of  wood  alcohol;  thus: 

CH3 
CH3-COO.  I 

^Ca  +   heat   =C  =  0+CaCo3 
CHg^-COO^  1 

gray  lime  (calcium  CH3 

acetate)  r — 

acetone 

The  so-obtained  acetone  may  be  purified  by  adding 
sodium  bisulfite  solution  and  converting  it  into  the 
crystalline  acetone  sodium  bisulfite  which,  when 
filtered,  pressed  and  distilled  with  sodium  carbonate, 
gives  acetone: 

2(CH3)2  =  C(OH)— S03Na  +  Na^COg  =  2CH3— 
CO— CH3  +  2Na2S03  +  CO2  +  H2O. 

The  acetone  which  passes  over  is  dehydrated  by 
calcium  chlorid  and  redistilled. 

Description  and  Properties. — Acetone  (acetonum 
U.  S.  P.)  should  contain  not  less  than  99%  by  weight 
of  absolute  dimethyl  ketone.  It  is  a  colorless  liquid, 
with  a  fragrant  odor  similar  to  methyl  alcohol; 
soluble  in  water,  and  having  a  boiling-point  of  56° 
and  a  specific  gravity  of  0.792  (20°).  It  is  soluble 
in  water,  alcohol  and  other  organic  solvents.     It  is 


342  PHARMACEUTIC    CHEMISTRY. 

sometimes  contained  in  the  breath  of  diabetic 
patients  and  in  the  urine — in  which  it  may  be  de- 
tected by  the  iodoform  reaction  (Lieben's  test).  It 
is  employed  chiefly  as  a  solvent  for  nitrocellulose, 
with  which  it  forms  collodions  known  as  "acetone 
collodions."  It  is  also  used  as  a  solvent  in  the 
preparation  of  the  official  oleoresins,  and  in  the  manu- 
facture of  iodoform,  chloroform,  sulfonal,  etc. 

When  acetone,  mixed  with  twice  its  weight  of  70% 
sulfuric  acid,  is  subjected  to  distillation,  mesitylene 
passes  over.  Mesitylene  is,  chemically,  trimethyl 
benzene,  CgHjj,  and  may  be  said  to  be  a  conden- 
sation product  of  three  molecules  of  acetone  from 
which  three  molecules  of  water  have  been  removed. 

KETOLS  AND  MERCAPTOLS.— When  ketones 
unite  with  alcohols,  ketoh  are  formed: 

CH3  CH,  OC^H, 

\  c,H,oH       CH3       ogHs 

CR^  '  ketol. 

dimethyl 
ketone 

When  ketones  unite  with  mercaptans,  mercaptoh 
are  formed: 

CH3  CH,  SC3H, 

/  C,H,SH  \^/  HO 

\  C.H-SH  CH3  sgH, 

CH3  ethyl  mercaptol 

-. r   -!  mercaptan 

dimethyl 
ketone 

When  mercaptols  are  o.xidized,  they  take  up 
oxvgen   much   like   the   mercai)tans,    forming   com- 


SULFONAL  AND    TRIONAL.  343 

pounds  containing  sulfonic  acid.  Thus,  when 
mercaptol  is  treated  with  two  molecules  of  oxygen, 
diethylsulfondimethylmethane,  or  sulfonal,  is  formed, 
according  to  the  following  reaction: 

CH3  SQH.  CH3  SOXaHj 

^C^  +20=        "^C^ 

CH3  SCHs  CH3  SOo^CHs 


mercaptol  diethylsulfondimethylmethane. 

(sulfonal) 

SULFONAL  is  a  colorless,  tasteless,  inodorous, 
crystalline  body,  with  a  melting-point  of  125-126°  C. 
and  a  boiling-point  of  300°  C.  It  is  soluble  in  15 
parts  of  boiling  water,  500  parts  of  cold  water  and 
in  65  parts  of  alcohol.  It  is  used  as  a  hypnotic.  It 
is  official  under  the  title  sulphonmethane  (sulphon- 
methanum  U.  S.  P.). 

When  one  methvl  group  of  sulfonal  is  replaced 
CH3  SO2C2H5 

by  an  ethyl  group,      y  C  <^        TRIONAL  is  formed. 

C2H5  SO3C0H, 

It  is  prepared  by  the  oxidation  of  a  mercaptol  with 
ethylmercaptan.  It  is  official  as  sulfonethylmethane 
(sulphonethylmethanum  U.  S.  P.).  Trional  forms 
colorless,  shining  crystals,  melting  at  76°  C,  and 
soluble  in  320  parts  cold  water;  freely  soluble  in  hot 
water,  alcohol  and  other  organic  solvents. 

When  both  methyl  radicals  of  sulfonal  are  replaced 
C^H,  SO2C2H5 

by  ethyl  radicals,  /  ^  \  diethylsulfon- 

C3H3  SO^C.Hs 


344  PIIARMACKUTIC    CHEMISTRY. 

(liethylmethane  (TETRONAL)  is  ])roduce(i.  The 
method  of  prepanition  of  tetronal  differs  from  thai 
of  sulfonal  in  that  diethyl  ketone  is  employed  in  the 
place  of  acetone.  It  occurs  in  crystalline  scales, 
melting  at  89°  C,  soluble  in  450  parts  cold  water, 
readily  in  alcohol  and  other  organic  solvents. 

There  seems  to  be  some  connection  between  the 
hypnotic  action  of  sulfonal  and  the  ethyl  radicals  it 
contains,  for,  while  dimethylsulfondimethylmethane 
does  not  produce  sleep,  dimethylsulfondiethylmethane 
does.  Hence  the  supposition  that  trional  with  three, 
and  tetronal  with  four  ethyl  radicals  should  act  as 
stronger  and  safer  hypnotics  than  sulfonal,  and  by 
e.xperience,  the  supposition  has  been  confirmed. 


HH  CO  O 

S  Q  O 

>  O  U 

^  w  o 


g~ 

•;d-3uinoq  1 

O    i-> 

^^-______^^_^r~s-^      aq^  ^v 

tC  .^ 

O^oooooo      oooo     wr^ 

'o  "> 

" -^vS.vS-vSw-^-^^Aw^^^  1          1 

CJ    S 

^  N    ro  r^  lO^C    r^-i/iLriMi^MO     '     >o'     N 

'^^iTr 

r0UOi-.0CO>/-)-t-J-0-+i^<N"'r)         t^        ^ 

w  ^ 

nooono-onc-onoo.  c^c^c^c^      oo       oo 

►;K;wo'dddddddd6d       d       d 

O     9Jnss3Jd 

h 

^■uiuioonv 

~  o 

oooooocooooooooooo 

o  & 

MOOM      «      ^lOTJ-t--T)-0      ^O    VO    CO      lO    LOO      O 

O    -■    '*"0    iJ^OO    r^  t^vO    O    <^    ^O0O  O    t^  <N    ro  "O 

H,„„HMM^MMP)WNi-.<NMOI<N(N 

io 

+ 

c  -^ 

oo          o                       oooooo              o 

•z!  c: 

ro  uo        ii     1       1       1       1      -rf  u^  ir>  iri  w^  ^                lo 

5  g. 

odvo°r)-°ON                   LOMdvd<NM§o%t-d%- 

^  "^ 

II                 M 

ffi 

o 

ffiO 

d 

od 

u 

ffi 

d^ 

W 

o 

UKffiU 

c 

c 
c 

c 

8  3£ffi  ffi  £ffi  ffiVffi  w  ffi  ffi  ffi  ^o  ^«  ^.  ^. 

W  u  u  u  y,uB^By.u  u  u  u  u  u  u  u 

M       (1       C        p.        C< 

•11 

^6  6  6  644404^44%"^^%% 

jj?  W  ffi  ffi  K  K  K  S.ffi  ffi  tC  ffi  ffi  =^0 ^-  ^  ^^^^ 

n 

,  ,    n 

W>2 

U  U  U  CJ  U  U  U  UCJ  U  U  CJ  U  U  cJ  cJ  U  CJ 

:g 

•  ^-i 

1 
t3 

^ 

>.  rt   S   t. 

1 

!•- 

111 

o     ■ 

It 

i 

3    J 

H  < 

hP 

3    C 

5  - 

> 

1 

^ 

^ 

-1   re  c 
^CJ[i 

c! 

U 

'aL 

i_ 

^ 

^ 

1 

jutod 

^^ 

-3ui?[3iu  aqi  ly 

II 

d       d 

3Jnss3Jd 

•luiu    ooi    JV 

V^VSsI  1  1  M  1  1 

M    M     <N     N 

1 

is 

1'^ 

°uo°M  °o  °H  °vr5'r^°0  °M  't^oo    O 
lOO  vO    t^  l^  t--00    t^  r-.  t^  c^ 

1  O 

1  u 

a  w 

ao 

ooooo  • 

ooooo  ^ 
uuuuu  g 

UUUUUD 

g 

•  -  — 

ll 

UUUUUCJOUUUU 

»i2  eu  Q  w3  <  pa  hJ  u  ffi  u  ^ 


.  FATTY   ACIDS.  347 

When  methyl,  ethyl  or  propyl  alcohols,  all  of 
which  are  monatomic,  are  subjected  to  oxidation, 
they  are  converted  first  into  aldehyds,  which  take 
up  oxygen  and  are  converted  into  acids.  The 
relationship  is  shown  in  the  following  table: 

Hydrocarbons — .Alcohols — .Aldehyds — >  Acids 

CH4  — .  CH4O  — .  CH2O  —  CH202=   formic  acid 

C2H6       —  C.HeO—  C2H4O— .  C2H40,=  acetic  acid. 
C3H8       —  C3H8O  —  CjHsO^  CjHsOj.    Propionic 

acid. 

All  the  above  acids  contain  but  two  oxygen  atoms 
in  the  molecule  or  one  COOH  (carboxyl)  group,  and 
are  spoken  of  as  monobasic  acids. 

When  diatomic  alcohols,  are  subjected  to  oxi- 
dation, acids  having  four  oxygen  atoms  in  the 
molecule  or  two  carboxyl  groups  are  formed,  and 
are  spoken  of  as  dibasic  acids.  Similarly,  we  have 
tribasic  acids  and,  if  in  addition  to  the  carboxyl 
groups  they  contain  also  one  or  more — OH  (hydroxyl) 
groups,  they  are  spoken  of  as  atomic  acids;  thus, 
tartaric  acid  has  two  hydroxyl  groups  and  two 
carboxyl  groups  and  is,  therefore,  spoken  of  as 
dibasic  and  diatomic.  All  organic  acids  contain 
at  least  one  carboxyl  radical  or  group.  The  car- 
boxyl radical  is  sometimes  known  as  oxatyl, — COOH, 
and  is  monovalent.  The  simplest  organic  acid  in 
which  the  carboxyl  is  united  to  hydrogen  is  formic 
acid,  H — COOH,  and  the  series  of  acids  of  which  it 
is  the  first  and  simplest  member  are  sometimes 
called  formic  acid  or  the  fatty  acid-series. 

The  basisity  of    an  organic  acid  depends  upon 


348  1'1I.\K.MA(  Kl  lie    CIlKMISIkV. 

the  number  of  carboxyl  groups  contained  in  the 
molecule.  Thus,  formic  acid  contains  one  carboxyl 
group  and  is,  therefore,  monobasic;  oxalic  acid 
contains    two    carboxyl    groups    and    is,    therefore, 

COOH 
dibasic    [  ;  and   citric   acid,  containing   three 

COOH 
carboxyl  and  one  hydroxyl  group,  is  called  a  tribasic, 
monatomic    acid.     Acids   containing   the    hydroxyl 
group  in  addition  to  the  carboxyl  are  also  spoken 
of  as  oxy-  or  hydroxy  acids. 

In  this  discussion  no  attempt  will  be  madt  to 
cover  all  the  acids,  but  only  those  of  pharmaceutic 
importance  will  be  taken  up. 

Properties. — The  organic  acids  are  feebler  than 
the  inorganic  acids,  but  otherwise  possess  the  same 
general  properties.  The  higher  and  more  complex 
acids  are  very  weak  in  their  acidic  properties.  A  salt 
of  an  organic  acid  and  a  non-volatile  metal,  and  upon 
incineration,  is  converted  into  the  metallic  carbonate. 
There  are  several  homologous  series  of  these  organic 
acids,  but  the  most  important  is  the  fatty-acid  series, 
which  derives  its  name  from  the  fact  thai  some  of  its 
higher  members  are  found  as  salts  of  the  glyceryl 
radical  in  fats.  Many  of  the  acids  of  this  series,  are 
found  in  nature;  thus  formic  acid,  which  is  the  first 
member  of  the  series,  is  found  in  stinging  nettle  and 
red  ants.  The  second  acid  of  the  series  is  acetic 
acid,  which  occurs  in  many  plants,  in  certain  animal 
secretions,  and  can  be  readily  distilled  from  vinegar. 
Butvric  acid,  the  fourth  member  of  the  series,  is  found 


FORMIC   ACID.  349 

in  rancid  butter,  and  valeric  acid,  the  fifth  member, 
is  found  in  valerian  root,  etc. 

Occurrence. — Besides  the  above  sources,  the  higher 
acids  are  found  in  the  animal  fats,  in  the  fats  of 
plants,  and  free  and  combined  as  metallic  and 
ethereal  salts. 

Varieties. — Above  we  have  mentioned  the  simple 
and  the  hydroxy  acids.  Besides  these  we  have  chlor- 
acids  which  are  formed  when  the  hydrogen  of  an  acid 
radical  is  replaced  by  chlorin.  When  the  hydrogen 
of  the  acid  radical  is  replaced  by  NHj,  amido  acids  are 
obtained;  when  one  of  the  oxygens  of  the  carboxyl 
group  is  replaced  by  sulfur,  thio-acids  are  produced. 

Preparation. — Several  methods  of  preparation  are 
known:  (i)  By  decomposing  metallic  salts  with 
sulfuric  or  hydrochloric  acids;  (2)  by  saponification 
of  the  esters;  (3) by  fermentation;  (4)  by  destructive 
distillation;  (5)  by  oxidation  of  the  corresponding 
alcohols;  (6)  by  hydrolysis  of  the  hydrocarbon 
cyanids  with  alcoholic  potash. 

Characteristics  0}  the  Series. — The  fatty  acids  form 
a  homologous  series,  of  which  the  first  nine  members 
are  colorless  liquids,  showing  a  rise  of  about  22° 
in  their  boiling-points  for  each  CH2  group  added; 
thus,    butyric    acid    boils   at    163.2°;   valeric    acid, 

184.5°. 

Beginning  with  pelargonic  acid,  C9H19COOH, 
which  is  a  solid,  all  the  higher  members  are  also 
solids. 

FORMIC  ACID,  H— COOH  or  HCHO.,  can  be 
prepared  by  the  oxidation  of  methyl  alcohol  either 


350  pnARMAC?:uTic  chemistry. 

by  dropping  it  on  spongy  platinum  or  by  distilling 
methyl  alcohol  with  potassium  dichromate  and 
sulfuric  acid.  This  latter  mixture  in  presence  of 
alcohol  evolves  oxygen  with  formation  of  potassium 
and  chromium  sulfates: 

CH,OH  +  02=HCOOH  +  H20 

formic  acid 

Formic  acid  can  also  be  prepared  by  heating 
glycerol,  with  oxalic  acid  to  about  ioo°  C,  when 
formic  acid  will  form  and  distill  over  with  the  water, 
while  another  portion  of  it  combines  with  the 
glycerol,  forming  glyceryl  monoformate.  This  second 
portion  can  be  recovered  and  a  second  quantity 
of  formic  acid  obtained  by  the  addition  of  more 
crystallized  oxalic  acid  and  continued  heating. 
The  glycerol  takes  no  part  in  the  production  of  the 
formic  acid,  but  modifies  the  method  of  decom- 
position of  oxalic  acid: 

CO  OH 
I  =HCOOH  +  CO, 

CO  OH  formic  acid 

oxalic  acid 

rropoiics. — Formic  acid  is  a  clear,  colorless 
liquid  with  a  i)ungent,  penetrating  odor,  boiling  at 
ioi°C.,and  having  a  specific  gravity  of  1.231  (10°). 
In  the  concentrated  form  it  produces  a  blister 
when  applied  to  the  skin.  All  its  salts  are  soluble 
in  water,  and  these  as  well  as  the  acid  are  decom- 
posed by  strong  sulfuric  acid  with  effervescence, 
yielding  carbon  monoxid.  Pure  carbon  monoxid 
mav  readily  l)c  obtained  b\'   healing  llic  acid   with 


ACETIC   ACID.  351 

Strong  sulfuric  acid,  the  latter  acting  as  a  dehydrating 
agent: 

HCOOH— H3Q  =  CO 

formic  acid  carbon  monoxid 

Formic  acid  and  its  salts  are  strong  reducing 
agents.  On  warming  a  few  drops  of  it  with  an 
ammoniacal  solution  of  silver  nitrate,  a  silver,  mirror- 
like deposit  will  form.  This  reaction  distinguishes 
formic  acid  from  all  the  other  fatty  acids,  and  is  due 

\H- 

The  above  is  the  principal  test  for  the  acid  and  the 
formates. 

ACETIC  ACID,  CH3COOH,  is  official  in  the  Phar- 
macopoeia in  three  forms:  acidum  aceticum,  con- 
taining 36%;  the  dilute  (dilutum),  6%,  and  the 
glacial  (glaciate),  99%,  respectively,  of  the  absolute 
acid. 

Acetic  acid  may  be  obtained  by  one  of  two  prin- 
cipal methods:  First,  by  the  oxidation  of  alcohol; 
second,  by  the  dry  or  destructive  distillation  of  wood. 
By  the  first  method  we  obtain  vinegar;  by  the 
second,  crude  acetic,  or  pyroligneous  acid. 

Vinegar. — When  weak  alcoholic  solutions,  such 
as  wine,  beer  or  cider,  are  exposed  to  the  air,  the 
vinegar  organism  (mycoderma  aceti),  also  known 
as  "mother  vinegar"  or  acetous  ferment,  starts  the 
fermentation.  Strong  alcoholic  liquids — i.e.,  those 
containing  more  than  15%  of  alcohol — prevent  the 
activity  of  the  organism.  The  10%  alcoholic  solutions 
are   the   most  favorable.     The  organism  acts  as  a 


352  PHARMACEUTIC    CHEMISTRY. 

carrier  or  "fixer"  of  oxygen  between  the  air  and  the 
alcohol.  Thus,  we  produce,  by  employing  beer, 
mali  vinegar;  by  employing  wine,  wine  vinegar, 
containing  6%  and  8%  of  acetic  acid,  respectively. 
Wine  vinegar  owes  its  aroma  to  ethyl  acetate  and 
proprionate  and  other  substances  present  in  the 
wine. 

Quick  Vinegar  Process.  —  In  this  "oxidation 
method"  a  dilute  alcoholic  solution,  not  over  io% 
strong,  is  permitted  to  slowly  drop  into  a  large  cask 
perforated  with  holes  for  free  admission  of  air  and 
filled  with  clean  wood  shavings.  Some  warm, 
fermented  malt  liquor,  such  as  beer,  is  poured  upon 
the  shavings  and  acts  as  the  "mother  of  vinegar," 
or  as  the  ferment.  The  alcoholic  solution  dripping 
through  the  cask  when  it  comes  in  contact  with  the 
shavings  coated  with  the  ferment  organisms,  becomes 
oxidized,  the  temperature  of  the  cask  interior  rises, 
causing  a  free  circulation  of  air,  and  the  alcoholic 
solution  is  rapidly  converted  into  an  impure  solu- 
tion of  acetic  acid  which  issues  from  an  orifice  at 
the  bottom  of  the  cask.  By  distilling  vinegar  we  can 
obtain  the  free  acetic  acid. 

Second  Method.— As  stated  under  the  destructive 
distillation  of  wood,  the  aqueous  solution  produced 
therein,  known  as  pyroligneous  acid  (containing 
acetic  acid,  methyl  alcohol  and  acetone),  is  permitted 
to  run  into  milk  of  lime,  forming  crude  calcium 
acetate.  When  crude  lime  acetate  is  subjected  to 
distillation,  methyl  alcohol  and  acetone  are  distilled 
off.     The    dry    acetate    is   next    distilled    in    cojipcr 


ACETIC  ACID — PROPERTIES.  353 

vessels  with  sufficient  quantity  of  strong  hydrochloric 

acid  to  decompose  it: 

(CH3— COQ^Ca  +  2HCI  =  2CH3COOH  +  CaCI^ 

calcium  acetate  acetic  acid 

The  distillate  contains  about  50%  of  acetic  acid, 
which  is  further  purified  by  distillation  over  a  little 
potassium  dichromate.  Glacial  acetic  acid  is  made 
by  neutralizing  the  ordinary  strong  acetic  acid  with 
soda.  This  forms  a  compound  crystallizing  with 
three  molecules  of  water  and  having  the  formula 
CHgCOONa  +  3H2O.  When  fused,  water  of  crys- 
tallization is  expelled,  and,  upon  addition  of  con- 
centrated sulfuric  acid  and  distillation,  the  salt  is 
decomposed  and  pure  acetic  acid  passes  over.  The 
pure  acid  solidifies  on  cooling,  forming  a  crystalline 
mass  resembling  ice,  from  which  its  name  "glacial" 
has  originated.  It  melts  at  16.7°  and  boils  at  119°, 
and  has  a  specific  gravity  of  1.049. 

Properties,  Uses  and  Tests. — Acetic  acid  is  a  useful 
solvent  for  organic  substances  because  it  is  little 
affected  by  oxidizing  agents.  When  it  is  mixed 
with  water,  contraction  in  volume  takes  place  so 
that  an  aqueous  solution  frequently  has  a  higher 
specific  gravity  than  the  pure  acid,  and  for  this 
reason  the  strength  of  acetic  acid  cannot  safely  be 
determined  by  hydrometer.  It  can  be  detected  by 
its  odor  or  by  neutralizing  the  liquid  with  soda  and 
evaporating  to  dryness.  If  sulfuric  acid  is  now 
added  to  the  residue,  strong  odor  of  vinegar  develops, 
and,  in  the  presence  of  a  little  alcohol,  the  fragrant 
odor  of  ethyl  acetate  will  develop.  With  ferric  chlorid, 
23 


354  1'HARMACF.UTIC    CHEMISTRY. 

acetic  acid  and  the  neutral  acetates  will  give  a  deep 
red  coloration,  which  is  destroyed  on  boiling,  forming 
an  insoluble  basic  salt.  Formic  acid  gives  similar  re- 
actions, but  it  can  be  distinguished  from  acetic  by  its 
reducing  power  on  silver  nitrate  solutions — a  property 
not  possessed  by  acetic  acid.  With  silver  nitrate, 
aqueous  solutions  of  acetates  give  a  characteristic 
crystalline  precipitate  of  silver  acetate  which,  when 
dried  and  ignited,  leaves  a  residue  equal  to  64.6%  of 
metallic  silver.  By  this  means  a  quantitative  deter- 
mination of  the  most  satisfactory  kind  is  made  and 
also  serves  as  a  method  for  identifying  organic  acids. 
Many  salts  of  acetic  acid  are  official,  of  which  the 
most  common  is  lead  acetate,  "sugar  of  lead," 
Pb(CH3COO)2,3H20.  This  is  obtained  by  dissolv- 
ing lead  carbonate  in  acetic  acid,  evaporating  and 
crystallizing.  A  solution  of  the  normal  salt  dissolves 
lead  oxid  (litharge)  and  forms  basic  acetate  of  lead 
(subacetate),  PbjOCCHgCOO)^-  This  is  the  chief 
ingredient  of  Goulard's  extract  (liquor  plumbi  sub- 
acetatis  U.  S.  P.).  This  solution  exposed  to  the 
air  turns  milky  through  the  absorption  of  CO.  gas. 
All  soluble  compounds  of  lead  are  poisonous,  and 
magnesium  or  sodium  sulfates  serve  as  reliable  anti- 
dotes, because  they  form  with  it  insoluble  lead  sulfate. 
"Iron  liquor"  is  a  solution  of  the  acetate  of  iron, 
and  "red  liquor"  is  a  solution  of  aluminum  acetate, 
both  used  as  mordants  in  calico  dyeing  and  printing. 

The  calcium  salt  of  acetic  acid  is  used  in  tlic 
manufacture  of  acetone. 

PROPIONIC     ACID,     CH.C'H.C'OOH,     is     m<.st 


BUTYRIC   ACID.  355 

readily  obtained  by  oxidizing  propyl  alcohol  with  a 
"pyrochromic  mixture."  (Pyrochromic  mixture  is  a 
solution  of  potassium  dichromate  in  concentrated 
sulfuric  acid,  and  is  the  most  commonly  used  oxidiz- 
ing agent -of  organic  chemistry.)  Propionic  acid  is 
found  among  the  products  of  certain  fermentative 
processes.  It  is  soluble  in  water,  but  is  thrown 
out  of  its  solution  when  calcium  chlorid  is  added. 
Otherwise,  it  resembles  acetic  acid  in  odor  and 
appearance  and  its  properties,  but  has  a  boiling- 
point  of  141°  C.  It  may  be  synthetized  by  hydro- 
lyzing  ethyl  cyanid  (QHjCN) : 

C,H.— CN  +  2H2O  =  C2H5COOH  +  NH3. 
BUTYRIC  ACID,  CH3— CH^— CH^— COOH,  oc- 
curs in  two  isomeric  modifications:  Normal  or  fer- 
mentation butyric  acid  (Chevreul,  1814),  first  found 
in  butter,  in  which  it  is  present  to  the  extent  of  about 
7%  as  a  glyceryl  ester.  It  is  also  found  in  the  free 
state  in  perspiration  and  in  certain  animal  secretions. 
The  principal  source  of  it  is  the  fermentation  known 
as  "butyric."  By  mixing  a  solution  of  starch  with 
putrid  cheese  and  chalk  in  presence  of  tartaric  acid 
and  ammonium  phosphate  at  a  temperature  of  about 
35°  C,  butyric  acid  is  formed.  It  may  be  said  that 
the  fermentation  takes  place  in  several  stages;  thus, 
the  starch  is  first  converted  into  glucose,  this  into 
lactic  acid,  and  lactic  acid  into  butyric  acid: 

(1)  CeH^.O,    =    2C3He03 

glucose  lactic  acid 

(2)  2C3H,03   =   C.HsO,   -f-   2CO,   -h   2H, 

butyric  acid 


356  PHARMACEUTIC    CHEMISTRY. 

Among  the  products  of  this  fermentation  besides 
the  butyric  acid,  acetic  and  caproic  acids  may  be 
mentioned.  The  free  butyric  acid  produced  com- 
bines with  the  calcium,  forming  calcium  butyrate, 
which  is  decomposed  by  hydrochloric  acid,  and 
butyric  acid  is  separated  by  distillation.  It  may  also 
be  obtained  by  oxidizing  normal  butyl  alcohol. 
Butyric  acid  is  an  oily  liquid,  possessing  an  un- 
pleasant odor  of  perspiration  and  rancid  butter. 
It  is  soluble  in  water  but,  like  propionic  acid,  it  is 
thrown  out  of  solution  by  calcium  chlorid.  Its 
ester  (ethyl  butyrate)  is  employed  in  making  arti- 
ficial flavoring  essence  of  peach.  Isohntyric  acid 
has  been  found  free  or  as  an  ester  in  many  plants. 

It  has  the  formula  ^^^^CH—COOH.    It  is  found 

in  the  oil  of  chamomile,  or  may  be  prepared  by 
oxidizing  isoljutyl  alcohol  or  by  the  hydrolysis  of 
isobutyronitril  (isopropylcyanid).  In  appearance  it 
closely  resembles  the  normal  acid,  but  is  less  soluble 
in  water,  and  its  calcium  salt  is  more  soluble  in  hot 
than  in  cold  water. 

VALERIC  ACIDS.— "Valerianic"  acid  has  the  form- 
ula C3H,o02  and  exists  in  four  isomeric  modifications. 
Two  of  the  isomerids,  the  isovaleric  and  methyl- 
ethyl  acetic  acids,  are  obtained  by  the  oxidation  of 
fusel  oil.  Isovaleric  acid  occurs  as  a  glycerid  in 
certain  blubber  oils.  The  above  two  acids  are 
found  together  in  the  valerian  group  and  in  angelica, 
from  which  they  may  be  obtained  by  distilling  with 
water.     Thev    are    c)il\-    li((ui(ls,    slightly    soluble    in 


VALERIC  ACIDS.  357 

water.  One  of  these,  however,  the  methyl-ethyl 
acetic  acid,  exists  in  two  modifications  which 
cannot  be  distinguished  in  appearance  or  by  chemical 
properties,  but  which  differ  in  certain  physical 
[)roperties,  namely,  it  is  "optically  active" — that 
is,  it  affects  the  plane  of  polarized  light.  All  bodies 
possessing  this  property  are  known  as  "optically 
active"  and  must  contain  at  least  one  asymmetric 
carbon  atom.  An  asymmetric  carbon  atom  is  one 
in  which  each  of  the  four  bonds  is  united  to  a  different 
atom  or  group.  The  following  are  the  structural 
formulas  of  the  four  valeric  acids,  the  third  one  of 
which  is  optically  active  because  it  contains  one 
asymmetric  carbon  atom: 

CH3 


nonnal  valeric  acid  (propylacetic  acid) 
CH3. 

>CH-CH3-COOH 

CJJ  /  isovaleric  acid  (isopropy- 
^  lacetic  acid.) 

CH3  CH3 

I        '  I 

C2H5-C-H  CH3-  C-COOH 

I  1 

COOH  CH, 


active  valeric  acid  (me-  trimethylacetic  acid, 

thylethyl  acetic  acid) 

Commercially,  isovaleric  acid  is  obtained  by  the 
oxidation  of  the  commercial  amyl  alcohol  with 
pyrochromic  mixture,  and  this  is  the  source  of  the 
valerates  employed  in  medicine.  Valeric  acid  has 
an  unpleasant,  rancid  odor,  a  boiling-point  of  170° 
C.  and  a  specific  gravity  of  0.941  (at  0°  C). 


358  PHARMACEUTIC    CHEMISTRY. 

The  higher  homologues  of  the  paraffinic  acids  occur 
frequently  in  the  fats  and  oils  and  have  been  de- 
scribed under  Fats. 

LAURIC  ACID,  CnHjgCOOH,  occurs  in  the  seeds 
of  the  laurel — Laurus  nohilis — and  in  the  wood  of 
the  South  American  Goupia  tomentosa. 

MYRISTIC  ACID,  Ci^H^COOH,  is  found  in  the 
seeds  of  the  wild  nutmeg — Myristica  moschata. 

MARGARIC  ACID,  C.^B^^COOYi,  does  not  seem 
to  occur  in  the  common  fats,  but  it  can  be  prepared 
synthetically. 

ARACHIDIC  ACID,  CigHgeCOOH,  occurs  in  the 
African  earth  nut — Arachis  hypogeia. 

THE  DIBASIC  ACIDS. 
I  ^  \C()C)HJ 


Melting-point 


Carbonic  acid 

HO.CO.OH                        , 

Oxalic  acid 

COOH.COOH                   1 

189° 

Ma  Ionic  acid 

COOH.CHj.COOH 

134-° 

Succinic  acid 

COOH.CH..CH..COOH 

182.° 

Glutaric  acid 

COOH.(CH,)3.COOH     . 

97° 

Adipic  acid 

COOH.(CH,)4.COOH      , 

1^0.° 

Pimelic  acid 

COOH.(CH,)s.COOH 

103.° 

Preparation  0}  the  Dibasic  Acids. — The  dibasic 
acids  are  prepared  by  a  process  resembling  the 
formation  of  the  fatty  acid  series.  The  glycols, 
which  name  is  applied  to  the  diatomic  alcohols, 
and  which  possess  two  primary  alcohol  groups,  yield, 
on   oxidation,   dibasic   acids.     The   simi)losl   of   the 


CARBONIC   ACID.  359 

dibasic  acids  and  corresponding  to  the  first  glycol  is 
oxalic  acid: 

CHoOH  CO -OH 

I  +20,=  I  +2H2O 

CH3OH  CO -OH 

ethylene  glycol  oxalic  acid 

It  will  be  seen  from  the  above  that  two  oxygen 
atoms  have  been  substituted  for  each  two  hydrogen 
atoms  of  the  hydrocarbons.  They  contain  two 
hydrogen  atoms  replaceable  by  metals  or  basic 
radicals.  They  can  also  be  formed  by  hydrolysis  of 
the  cyanogen  derivatives  of  the  monobasic  acids. 
Thus,  cyanacetic  acid  will  hydrolyze  with  water, 
splitting  off  ammonia  and  giving  malonic  acid: 

/COOH  /COOH 

CH2  +2H20  =  NH3+      CH, 

\CN  \COOH 


cyanacetic  acid  malonic  acid. 

They  can  also  be  produced  by  treating  dicyanids 
(R''(CN)2)  with  caustic  alkalis,  and  by  o.xidation  of 
diatomic  primary  alcohols  and  the  oxidation  of 
hydroxyacids. 

Besides  these  methods  they  may  be  obtained  by 
electrolysis. 

CARBONIC  ACID,  HO— COOH.  While  this  acid 
has  only  one  carboxyl  group,  its  compounds,  how- 
ever, are  those  of  a  dibasic  acid.  Its  metallic  salts 
are  fully  described  in  the  inorganic  part  of  this  book. 

CARBONYL  CHLORID,  carbonoxychlorid,  phos- 
Cl 
gene,  COx       ,  is   obtained  bv  the  direct  union  of 
CI 


360  PHARMACEUTIC    CHEMISTRY. 

carbon  monoxid  and  chlorin  in  sunlight  (Davy,  1811). 
Carbonyl  is  also  formed  when  chloroform  is  oxidized 
in  the  presence  of  air  and  light.  On  a  large  scale 
it  is  produced  by  passing  a  mixture  of  carbon 
monoxid  and  chlorin  through  heated  charcoal. 
Carbonyl  chlorid  condenses  to  a  liquid  at  8°,  and 
has  a  suffocating,  pungent  smell.  It  has  been  used 
for  the  manufacture  of  aniline  dyes  and  specially  of 
crystal  violet. 

UREA,  carbamid,  CO(NH2)2.  This  important 
amid  is  a  normal  constituent  of  urine  and  constitutes 
the  chief  form  in  which  the  waste  nitrogen  of  the 
system  is  eliminated.  It  may  be  said  to  be  derived 
from  two  molecules  of  ammonia  in  which  two  hydro- 
gen atoms  were  replaced  by  the  divalent  carbonyl 
group.     Its  constitutional  formula  is  the  following: 

C==0  .      It     may     be     prepared     by     evaporating 

urine  and  adding  to  it  strong  nitric  acid  when,  on 
standing,  yellow  crystals  of  urea  nitrate  wnll  be 
deposited.  These  are  collected  on  a  filter,  dis- 
solved in  boiling  water  and  decomposed  by  barium 
carbonate,  which  forms  barium  nitrate  and  frees  the 
urea.  This  is  then  evaporated  to  dryness  on  a 
water-bath  and  the  dry  residue  is  extracted  with 
boiling  alcohol,  the  solution  is  filtered  and,  when 
concentrated,  deposits  crystals  of  urea.  It  may  also 
be  produced  from  ammonium  cyanate  and  carbonyl 
chlorid,  both  of  which  methods  have  already  been 
described. 


DERRATIVES    Ol'    CARBONIC   ACID.  361 

Derivatives  of  Carbonic  Acid. — Carbonic  acid  is 
spoken  of  as  methane,  CH^,  in  which  two  hydrogens 
were  replaced  by  two  hydroxyl  groups  and  the  other 
two  hydrogens  by  one  oxygen.  Its  graphic  formula 
may  be  written; 

OH 

HO— C— OH;  or  more  compactly  C=0 

OH. 

According   to   the   above   structure,   sodium   acid 

OH 

carbonate  would  be  written,  C=0  ,  the  nor- 


0- 

-Na 

0- 

/ 

-Na 

mal 

sodium 

carbonate, 

c^o 

,  and 

ammon- 

\o- 

-Na 

^0— NH, 

ium 

carbonate, 

C=0 

\ 

•^           XTTT 

O— NH,. 

Allied  to  carbonic  acid  is  carhamic  acid;  although 
it  has  never  been  isolated,  its  ammonilim  salt  is  a 
constituent  of  the  official  ammonium  carbonate 
(ammonii  carbonas).     Thus  ammonium  carbamate, 


362  PHARMACEUTIC    CHEMISTRY. 

NH4.COO.NH2,  is  readily  obtained  by  passing  COj 
into  an  alcoholic  solution  of  ammonia  gas: 

/ 
2NH3  +  C()2  =  c=o 

The  Pharmacopoeial  salt  is  a  mixture  of  this  and 

/OH 

the  ammonium  acid  carbonate,  C^^O  ;and  its 

\ 

^ONH, 
formula  is:     NH,HC03.NH,NH,C0,. 

Official  ammonii:m  carbonate 


When  ammonium  carbamate  is  heated,  urea  is 
/NH,  /NH, 

formed:  CO  =    CO  +   HjO. 

\0— NH,      \NH, 

Urea  may,  therefore,  be  regarded  as  the  amid 
of  carbonic  acid;  that  is,  carbonic  acid  in  which 
both  the  hydroxyl  groups  have  been  replaced  by 
amid, — NHj,  groups.     It  is  often  called  carta  mid. 

Urea  is  found  in  the  urine  of  mammals;  thus,  the 
normal  daily  quantity  excreted  by  men  is  from 
40  to  50  grams  and  by  women  25  to  40  grams.  I'rca 
is  the  end-product  of  the  proteid  metabolism  in  the 
body,  and  represents  about  85%  of  total  nitrogen 
eliminated  by  the  body;  the  quantity  found  in  urine 
serves  as  a  measure  of  the  nitrogenous  metabolism 
in  the  human  bodv. 


OXALIC   ACID.  363 

OXALIC  ACID,  H2C20„2H20,  is  a  dibasic  acid;  it 
occurs  in  the  form  of  fine  crystals  containing  2  mole- 
cules of  water  of  crystallization.  Oxalic  acid  may 
be  prepared  in  several  ways:  (i)  By  oxidation  of 
sugars,  starches,  etc.,  with  nitric  acid;  (2)  on  the 
commercial  scale,  by  heating  saw-dust  with  caustic 
soda  to  250°  C.  Sodium  oxalate  is  produced  by  this 
method,  which  extracted,  with  lime  water,  is  decom- 
posed by  strong  sulfuric  acid  into  insoluble  calcium 
sulfate,  the  solution  containing  oxalic  acid  is  decanted, 
filtered,  evaporated  to  a  small  bulk  and  crystallized. 
Oxalic  acid  is  a  strong  poison;  it  occurs  naturally  in 
juices  of  many  plants,  like  sorrel,  rhubarb,  oak, 
cinchona,  etc.  It  has  been  used  for  suicidal  purposes; 
as  antidotes,  magnesia  (MgO),  slaked  lime  in  a  httle 
water,  or  mucilaginous  liquids  should  be  given  at 
once.  If  there  is  no  vomiting,  an  emetic  is  admin- 
istered. Neither  a  stomach  pump  nor  alkalis,  or 
their  carbonates  should  be  used. 

Tests. — With  calcium  chlorid  neutralized  with 
ammonia  water,  the  soluble  oxalates  give  a  crystalline 
precipitate  soluble  in  hydrochloric,  but  insoluble  in 
acetic  acids. 

Properties. — Oxalic  acid  is  one  of  the  very  strong- 
est organic  acids,  it  is  soluble  in  water;. at  100°  C. 
it  loses  its  water  of  crystallization;  it  sublimes  at 
155°  C;  when  treated  with  strong  sulfuric  acid,  it 
decomposes  into  water  and  the  two  carbon  oxids: 
H2C2O,  =  H2O  +    CO  +  CO2. 

Oxalic  acid  is  a  strong  reducing  agent,  it  decolor- 
izes   solutions  of    permanganates,   and  precipitates 


364  PHARMACEUTIC    CHEMISTRY. 

gold   and   silver.     It   forms   two   classes  of   salts — 
acid  and  ncrmal. 

Acid  potassium  oxalate,  "salts  of  sorrel,"  binox- 
alate  of  potassium,  occurs  in  sorrel,  is  used  in  eradi- 
cating iron  and  ink  stains  from  fabrics,  in  manicuring, 

COOH 
etc.;  it  has  the  formula  | 

COOK. 
Calcium  oxalate  is  found  in  many  plants,  also  as 
a  crystalline  deposit  in  urine;  it  has  the  formula — 
COO. 
I         >Ca. 
COO^ 
COONa 
Sodium  oxalate  is  |  ,  a  normal  salt. 

COONa 
All   ammonium,  potassium   and  sodium  oxalates 
are  soluble;  the  oxalates  of    the   other   metals   are 
practically  insoluble. 

MALONIC    ACID   is  a  very  valuable  reagent   in 
organic  syntheses;  it  has  the  formula: 
COOH 

I 
CH2 

I 
COOH 

SUCCINIC  ACID.— The  normal  succinic  acid  is 

obtained  by  hydrolvzing  /i-cyanpropionic  acid;  thus: 

CH^CNCH^COOH    +  2H2O  =  COOH  +  NH3. 

/a-cyanpropionic  acid  I 

CHj 

I 
CH2 

I 
COOH 


ISOSUCCINIC  AND    MALIC  ACIUS.  365 

It  is  prepared  by  dry-distilling  amber,  and  occurs  in 
gastric  contents. 

ISOSUCCINIC  ACID  is  obtained  by  hydrolyzing 
a-cyanpropionic  acid: 

CH3 

I      /COOH  +NH3 
CH3.CHCN.COOH  +  2H20=CH( 

^COOH 

When  nor  null  succinic  acid  is  heated  to  235°  C,  it 
yields  siucinic  anhydrid  and  water: 
COOH 

I 

CH2  CHj— CO. 

1=1  >0  +  H,0. 

CH^  CHj— CQ/ 

I  succinic  anhydrid 

COOH 

When  this  anhydrid  is  heated  in  ammonia  gas  = 
CH,.CO 

I  /NH,  succinimid  is  formed. 

CHj.CO^^ 

When  the  /^osuccinic  acid  is  heated  above  130°  C, 
it  decomposes: 

COOH     COOH         CH3 

\/  CH,       +   CO, 

CH  =       I 
I  COOH 

CH3  propionic  acid 

In  fact,  any  organic  acid,  in  which  two  carboxyls 
are  attached  to  the  same  carbon  atom  at  high  tem- 
peratures, splits  off  CO,  from  one  of  the  carboxyls. 

MALIC  ACID  is  found  in  unripe  apples  and  many 


366  PHARMACEUTIC    CHEMISTRY. 

other  fruits;  chemically,  it  is  hydroxy  succinic  acid, 
and 

COOH 

I 

has  the  formula     |  .     Malic  acid  can  be  pre- 

CH.OH 

I 
COOH 

pared  from  the  berries  of  mountain  ash.     Aspartic 

COOH 

CH2 

acid  is  aminosuccinic  acid:     |  ,  and  is  closely 

CH.NH2 

I 
COOH 

related  to  malic  acid. 

Malic  acid  crystallizes  with  difl&culty;  it  is  soluble 
in  water  and  alcohol;  and  iron  malate  (ferri 
pomatum)  is  mentioned  in  the  National  Formulary; 
it  is  a  very  efficient  form  of  iron  when  used 
internally. 

Closelv  related    to    aspartic   acid    is  asparaqin, 

CO.NH2 

I 
CH, 

chemicallv,  amino-succin-amic  acid,    |  ;  it 

CH.NH2 

I 
COOH 

occurs  ill  many  leguminous  plants;  it  is  soluble  in 

hot  water,  and  with  HNO.,  it  is  converted  into  malic 

acid. 


HYDROXYACIDS.  367 

HYDROXYACIDS. 

When  ethylene  glycol  is  oxidized,  qlycollic  aldehyd,- 
CH2OH 

I  ,  is    formed;    this    further  oxidized  yields, 

CHO 
the  corresponding  hydroxyacid— glycollic  acid. 

GLYCOLLIC  ACID,  CHo.OH.COOH,  occurs  natur- 
ally in  the  leaves  of  the  Virginia  creeper,  wild  vine, 
etc.,  and  is  prepared  by  treating  amidoacetic  acid 
with  nitrous  acid: 

CH.NH,  CH,OH 

(i)    1  +  HO.NO=  I  +  H,0  +  No, 

COOH  COOH 

or  by  the  action  of  moist  silver  oxid  on  monochlor- 
acetic  acid: 

CHXl  CH.OH 

(2)21  +  Ag.,0    =2  I  +   2AgCl. 

COOH  COOH 

The  above  are  two  general  reactions  jor  the  prepa- 
ration of  hydroxy  acids. 

Glycollic  acid  occurs  in  colorless  soluble  needles. 
Chemically,  it  may  be  regarded  as  hydroxyacetic 
acid. 

Substitution  of  this  kind  in  the  paraffin  derivatives 
leads  to  the  possibility  of  isomerism,  as  has  been 
stated  under  Valeric  Acid  (p.  357),  and  all  the 
fatty  acids  beginning  with  propionic  exhibit  this 
possibility.  Thus,  in  propionic  acid,  CH3.CH2.  — 
COOH,  the  substitution  may  take  place  in  the 
methyl  (CH^)  or  the  methylene  (CH^)  group,  so  that 
there  are  two  hydroxypropionic  acids  possible: 
iS-Hydroxy     propionic     acid,    CHjOH.CH^.COOH, 


368  PHARMACEUTIC    CHEMISTRY. 

and  a-hydroxypropionic  acid,  CHj.CHOH.COOH 
=  lactic  acid. 

Nomenclature. — For  the  purpose  of  identification 
of  the  isomerids  of  this  kind,  their  names  are  custom- 
arily prefixed  with  letters  from  the  Greek  alphabet. 
Thus,  the  position  where  the  substitution  has  occurred 
is  indicated  starting  with  the  carbon  atom  nearest  to 
the  carboxyl  group.  (To  understand  this,  study  the 
formulas  of  the  above  two  acids.) 

LACTIC  ACID,  a-hydroxypropionic  acid,  oxypro- 
pionic  acid,  H.C3H5O,  is  a  monobasic,  monatomic 

CH3 

\ 
acid,  its  graphic  formula  being    CH.OH    ;     it      is 

I 
COOH 

found  in  sour  milk  as  product  of  hydrolysis.  Thus, 
milk-sugar,  which  is  normally  present  in  milk  and 
has  the  formula  Q^HjjOn.HjO  through  the  fermen- 
tation induced  by  the  lactic-acid  ferment  (Bacillus 
acidi  lactici),  is  split  into  lactic  acid;  thus: 
C,3H,,0„.H,0  =  4C3H,03 

acid  lactic 

Lactic  acid  may  also  be  prepared  by  fermenting 
starch  paste  with  lactic-acid  ferment  or  by  heating 
cane-sugar  with  sodium  hydroxid. 

Lactic  may  be  synthesized  from  a-aminopropionic 
acid  by  one  of  two  general   methods  given  under 
Glycollic     Acid.     When     oxidized    with    potassium 
permanganate,  it  yields  pyruvic  acid. 
aCHvCH.qiLCOOH    -\-0,    =   ,CHi.Cq.C00H+2U,0 
acid  lactic.  pyruvic  acid. 


LACTIC   ACIDS..  369 

While  the  synthetic  lactic  acid  is  identical  in 
composition  and  reactions  with  the  acid  obtained 
by  fermentation,  this  latter  acid  differs  in  that  it  is 
"optically  active."  It  must,  therefore,  contain  an 
"asymmetric"  carbon  atom,  and  more  than  one  form 
of  it  should  be  known. 

In  reality  three  lactic  acids  are  known: 

(i)   Inactive  lactic  acid  (ordinary). 

(2)  Dextrolactic  acid. 

(3)  Levolactic  acid. 

Properties.— T\\t\r  chief  distinction  is  the  action 
on  polarized  light,  the  crystalline  structure  of  their 
salts  and  differences  in  solubility. 

When  ordinary  lactic  acid  forms  strychnine  salts, 
compounds  of  both  the  dextro-  and  levo-acid  are 
obtained  and  separated  by  crystallization.  Again, 
when  ordinary  mould  culture  (penicilium  glaucum) 
is  introduced  into  solutions  of  ordinary  lactic  acid, 
the  levo-acid  is  destroyed  by  the  bacteria  and  the 
dextro-acid  remains.  The  acid  is  official  as  a  75% 
solution  (acidum  lacticum)  and  its  graphic  formula 
showing  the  "asymmetric  carbon"  is  the  following: 
CH3 

I 
H  — C  — OH.  Sarcolactic  and  Paralactic  acids  are 

I 
COOH 

found  in  the  muscle  and  other  tissues  of  the  body, 

also  in  meat  extracts. 


CHAPTER  XXIX. 
DERIVATIVES  OF  THE  ACIES. 

As  stated  before,  acetic  acid,  when  subjected  to 
the  action  of  chlorin,  suffers  the  replacement  of  the 
hydrogen  atoms  of  the  methyl  group  CH3,  yielding 
three  chloracetic  acids: 

Monochlor acetic  acid,  CH2CI — COOH,  a  crystalline 
compound,  melting  at  62°  C. 

Dichloracetic  acid,  CHCU— COOH,  a  liquid,  boil- 
ing at  igo°  C. 

Trichloracetic  acid,  CCI3 — COOH,  ])repared  by 
oxidizing  the  aldehyd-chloral,  CCI3CHO,  a  crystal- 
line compound  melting  at  52°  C. 

What  has  been  said  of  acetic  acid  holds  true  with 
all  the  acids  of  the  formic-acid  series;  the  substitution 
always  taking  place  in  the  alkyl  group  and  never  in 
the  carboxyl  group.  These  halid  derivatives  re- 
tain the  characteristic  properties  of  the  acids  from 
which  they  are  derived,  since  the  carboxyl  group 
remains  intact. 

Acid  Chlorids. — When  phosphorus  trichlorid  reacts 
upon  alcohol,  it  replaces  the  hydroxyl  by  a  chlorin 
atom;  thus: 


^Cl     C.H, 
»-Cl-hC,K, 

-OH 
-OH 

^OH 
=  P-OH   + 

C,H,-C1 

C3H5-CI 

^Cl      C2H, 

-OH 

"^OH 

phosphorous 
acid 

C,H,-C1 
ethylchtorid 

370 


ACETYL    CHLORID.  37 1 

This  reaction  is  characteristic  of  phosphorus 
chlorid — with  all  substances  containing  the  hydroxyl 
groups. 

When,  therefore,  an  organic  acid  is  treated  with 
this  reagent,  the  hydroxyl  residue  of  the  carboxyl 
group  is  replaced  by  chlorin,  forming  an  acid  chlorid  : 

3CH3-COOH    =Pa3    =   3CH,C0-C1  +  H3P03 

acetic  acid  acid  chlorid  (acetyl 

chlorid) 

These  halid  derivatives  of  the  acids  are  named 
after  the  parent  acid.  Thus,  in  the  above  case 
''acetyl  chlorid"  with  propionic  acid  we  obtain 
"propionyl  chlorid,"  etc. 

The  student  should  observe  the  difference  in  the 
production  of  monochloracetic  acids  and  of  acetyl 
chlorid.  In  producing  the  first  class  of  compounds, 
the  halogens — chlorin,  bromin,  etc. — replace  the 
hydrogen  of  the  alkyl,  while  in  the  production  of 
acetyl  chlorid  the  phosphorus  trichlorid  replaces  the 
hydroxyl  (OH)  in  the  carboxyl  (CO— OH)  group 
bv  chlorin. 

ACETYL  CHLORID,  CH3— C— CI,  is  a  colorless, 
pungent  liquid,  fuming  in  contact  with  moist  air. 
With  water  it  hydrolyzes  into  acetic  and  hydrochloric 
acids  and  w-ith  alkali  hydroxids  into  corresponding 
acetates  and  chlorids. 

Acetyl  chlorid  is  a  valuable  reagent  in  organic 
chemistry  in  that  it  reacts  tvith  all  substances  con- 
taining the  hydroxyJ-groups,  forming  acetyl  dcriva- 


372  PHARMACEUTIC    ClI  F.MISTRY. 

lives.     It   acts    by   replacing    the    hydrogen  of    the 
hydroxvl    groups   bv   the  monovalent  acetvl  group: 

CH3-C(^ 

Alcohols,  therefore,  can  be  converted  into  alkyl 
acetates  or  acetic-acid  esters: 

C.H5OH  +  CHj  —  CO  — C 1  =  CHs  — O— CO— CH, + HC 1 

alcohol  acetyl  chlorid  ethyl  acetate 

The  saturated  acids  and  their  alkali  salts  when 
treated  vi^ith  acetyl  chlorid  have  their  hydrogen 
of  the  carboxyl  group  or  the  alkali  metal  replaced 
by  the  acetyl  group,  producing  a  new  class  of  organic 
substances,  namely,  the  acid  anhydrids: 

CH,^-COOK  +  CH.,  -  COCl  = 

acetic  acid 

CH3  -  CO  - 0  -co  - CH,  +  K(1 

anhydrid  of  acetic  acid  (acetic 

anhydrid) 

With  the  higher  homologues  oi  acetic  acicl 
])hospliorus  chlorid  reacts  similarly,  producing  corre- 
s[)onding  chlorids,  which  resemble  acetyl  chlorid  in 
pr()[)erlies. 

ACID  ANHYDRIDS.— These  are  produced  by  the 
interaction  of  acetyl  chlorid  and  the  alkali  salts  of 
the  acid,  as  shown  above.  If  we  employ  the  alkali 
salt  of  a  different  acid,  a  mixed  anhydrid  is  produced. 
Thus,  with  sodium  ])ro))ionate  acetyl  chlorid  })ro- 
duces  acetic-i)ro|)i()nic  anhydrid: 

CH3COCI  +  CH3  — CH2  — COONa  =  CH3— 
CO— ()— COCH.-CH,  -f  NaCl. 


ALKYL-SULFONIC    ESTERS   AND    ACIDS.  373 

The  anhydrids  bear  the  same  relation  to  the  acids 
as  the  ethers  do  to  the  class  of  alcohols: 

C2H5OH  . '  QH— O— QH, 

ethyl  alcohol  ethyl  ether 

■--— (di-ethyl-oxid) 

(CH3— CObH      . .       CH3— CO— O— CO— CH3 

-   acetie-acid  acetic  anhydrid  (di-acetyl-oxid) 

ACETIC  ANHYDRID,  (CH3— CO).©,  made  by  a 
process  described  above,  is  a  colorless  liquid  with  a 
pungent  acetous  odor  and  a  boiling-point  of  138°  C. 
It  combines  with  water  slowly,  forming  acetic  acid, 
and  with  hydroxylic  compounds  acetyl  derivatives; 
thus: 

CH3— OH  +  CH3CO— O— COCH3  = 
CH3— O— COCH3  +  CH3COOH 

methylacetate 

ALKYL-SULFONIC  ESTERS  AND  ACIDS.— When 

ethyliodid  is  warmed  with  sodium  sulfite,  ethyl-sul- 
jonic  acid  is  formed;  when  ethyl  mercaptan  is  sub- 
jected to  direct  oxidation,  the  same  compound  forms: 

2C2H5— HS       +        3O2       =     2C2H— HSO3 
ethyl  mercaptan  ethyl-sulfonic  acid 

When  thionyl  chlorid  (SOCU)  acts  upon  alcohol, 
ethyl  sulfite  is  formed: 

/CI  /O.C2H5  +  2HCI 

2C2H5— OH  +  SO<       =SO< 

_  Vl  ^O.C^H, 

thionyl  ethyl  sulfite 

chlorid 

Sulfonic  acids  possess  acid  reactions;  they  form 
salts  with  metals  and,  when  treated  with  phosphorus 
trichlorid,  are  converted  into  alkvl  sulfonic  chlorids; 


374  PHARMACEUTIC    CHEMISTRY. 

thus  ethyl-sulfonic  acid  yields  ethyl-sulfonic  chlorid, 
C2H5 — SO2 — CI.  Tliis  reaction  indicates  that  the 
sulfonic  acids  contain  a  hydroxyl  group. 

NITROGEN    IN    ORGANIC    COMPOUNDS    AND 
THEIR  DERIVATIVES. 

In  Chapter  XX\'I  the  cyanogen  derivatives  were 
treated  of;  all  the  other  nitrogen  compounds  of 
pharmaceutic  interest  will  be  briefly  treated  in  this 
chapter. 

Nitrogen  occurs  in  organic  compounds  as  cyano- 
gen, as  nitric  or  nitrous  acids,  ammonia,  and  their 
derivatives. 

Thus,  nitric  acid  enters  organic  compounds  by 
combining  with  organic  radicals,  as,  for  example, 
in  nitroglycerol.  Many  of  the  organic  compounds 
with  nitric  acid,  are  explosive. 

Nitro-derivatives  oj  the  Paraffins  include  those 
compounds  wherein  the  NOj  group  replaces 
the  hydrogen  of  carbon  compounds  when  these  are 
treated  with  concentrated  nitric  acid.  While  the 
paraffin  hydrocarbons  can  only  indirectly  have 
their  hydrogen  re]>!accd: 

CH3CI  +  .AgNo.,  =  CH3.NO.,  +  .\gCI. 

nitromethane 

Using  a  paraffin  derivative  and  a  salt  of  nitrous 
acid,  the  aromatic  hydrocarbons  can  be  treated 
directly  with  PINOg: 

C„H„  +  HNO3  =  CoHsNOj  +  HjO 


THE    NITRILS.  375 

The  nitroderivatives,  while  exhibiting  the  prop- 
erties of  the  ethers  of  nitrous  acid,  are  far  more 
stable. 

NITROETHANE,  C2H5.NO2,  obtained  similarly  to 
nitromethane,  is  a  colorless  liciuid,  with  a  pleasant 
ethereal  odor,  and  a  boiling-point  of  113°  C.  In 
composition,  nitroethane  is  identical  with  ethyl 
nitrite,  but  it  differs  in  structure  and  properties; 
thus: 

C2H,.Q.N0  C2H5  —  n:^ 

ethyl  nitrite  O 

nitroethane 

When  nitroethane  is  treated  with  nascent  hydrogen 
it  is  reduced  to  an  amin: 

QH^.Nf     -f3H2  =  C2H,.NH2-f2H3Q 

O  ethylamin 

While   ethyl    nitrite    similarly    treated,    gives    ethyl 
alcohol  and  ammonia: 

C^H^O.N:©  +3H2  =  C2H50H.  +H3O.  +NH3. 
When  nitroethane  is  treated  with  an  alkali  hydroxid, 
sodium  nitroethane  is  formed: 

//^  //^ 

C,H-.NC       +  NaOH  =  CH^NaNf       +  H,0. 

Ethyl  nitrite,  similarly  treated,  gives  alcohol: 
C,H5.0.N0  +  NaOH  =  QH^OH  +   Na.O.NO. 
THE  NITRILS.     In  Chapter  XXV  methyl  cyanid, 
CHj.C^N,   was  briefly  treated.     The  importance 
of  the  nitrils  is  in  the  syntheses  of  the  higher  carbon 
compounds.     Thus,  we  can  pass  from  a  one-carbon- 


376  PHARMACF.UTIC    CHEMISTRY. 

atom  compound  to  a  iu'o-carbon-a.tom  compound, 
then  to  a  tliree-carbon-a.toin  compound,  etc.: 

CH3.CJI.,CEEN  +  2H2O  =  CHaCH^.C^^         +  NH3 

ethyl  cyanid  (Jxl 

propionic  acid 

It  can  be  readily  seen  that  propionic  acid  having 
three  carbon  atoms,  is  a  derivative  of  propane,  and 
yet  ethyl  cyanid  is  prepared  from  ethyl  iodid,  which 
has  but  two  carbons  in  the  molecule: 
CH3.CH2.I    +   KCN     =     CHg.CH^.C^N   +  KI. 

The  nitrils  can  also  be  obtained  by  heating  the 
corresponding  ammonium  salts  with  phosphorus 
pentoxid;  thus: 

2CH3CQONH,  +  P3O5 

ammonium  acetate 

2CH3.CN  +  2H3PO,  +  H2O, 

methyl-cyanid 
(acetonitril) 

and 

2C2H5COONH, +  P2O5 

ammonium  propionate 

2C,H3.CN         +         2H3PO,         +         H3O 

ethylcyanid 
(propionitrile) 

It  will  be  seen  that  these  nitrils  are  named  after 
the  salts  from  which  derived;  thus,  acetonitril, 
propionitril,  etc. 

THE  ISOCYANIDS.— This  class  of  compounds  is 
a.\so  called  car  bam  ins.  Whereas  in  the  nitrils  the 
carbon  of  the  — C=N  is  directly  linked  to  the  other 
carbon  atom,  in  the  isocyanids,  it  is  the  nitrogen  of 
the  group  that  is  linked  to  the  carbon;  thus: 
:=N         —         CH,.N^C 


methyl  cyanid  methyl  tsocyanid 


FULMINIC   ACID.  377 

Of  all  the  metals,  silver  alone,  instead  of  a  cyanid, 
forms  an  wocyanid;  thus: 

AgNO,  +  K— C=N  =  KNO3  +  Ag— N=C. 
All  the  other  isocvanids  may  be  produced  by  heating 
the  alkyl  iodids  with  silver  cyanid. 

When  they  are  treated  with  water,  they  are  decom- 
posed differently  from  the  other  cyanids: 

,H  .0 

CH,— N=C  +  2H,0  =  CH3— N<      +H.Cf 


methyl  j'socyanid  methyl  amin  acid  formic 

The  isocyanids  are  readily  produced  by  heating 
together  any  amin  with  chloroform  and  caustic 
alkali: 

CH3NH2  +  CHCI3  +  3KOH  =  CHjN^C  + 


methyl  amin  +    chloroform  +     alkali     =     methyl  Mocyanid 
3KCI+3HP. 

Properties. — All  the  isocyanids  are  poisonous  and 
all  possess  a  suft'ocating  disagreeable  odor. 

FULMINIC  ACID.— Fulminic  acid  has  the  formula 
CNOH  according  to  theory,  although  it  has  never 

been  isolated.     Mercuric  fulminate  \\  /Hg, 

C=N.O/ 

crystallizes  with  half  a  molecule  of  water  =  CjNgOj.- 
Hg  +  ^HgO.  It  is  prepared  by  acting  with  alcohol 
on  a  mercuric-nitrate  solution  in  nitric  acid.  When 
dry,  the  salt  is  a  powerful  explosive  and  detonates. 
It  is  used  in  percussion  caps,  and  fired  by  a  fuse, 
sharp  blow  or  electricity. 


378  PHARMACEUTIC    CHEMISTRY 

CYANIC  AND  CYANURIC  ACIDS.— By  fusing 
together  potassium  cyanid  with  lead  oxid,  potassium 
cyanate,  KO  — C=N,  and  metallic  lead  are  produced. 
From  this,  cyanic  acid,  HO— C=N,  may  be  prepared. 
It  can  be  crystallized  from  alcohol,  but  in  aqueous 
solutions  it  decomposes  into  ammonia  and  carbon 
dioxid.  Cyanic  acid  can  also  be  prepared  from 
cyanuric  acid,  C3H3N3O3,  which  has  the  graphic 
formula  HO— C=N— C— OH 

1'  II 

N  =  C— N 

I 
O— H 

Cyanuric   acid  is  obtained  by  heating  urea: 
C3N3(OH)3    =     3HO.CN. 

cyanuric  acid  cyanic  acid 

When  cyanuric  acid  is  heated,  cyanic  acid  is  pro- 
duced: 

3CO(NH,)2  =  C3H3N303  +  3NH3. 

Cyanic  acid  is  a  strong,  unstable  liquid  which, 
above  0°,  polymerizes  rapidly  into  porcelain-like, 
opaque  mass,  called  cyamclide. 

Potassium  cyanate,  KO— CN,  is  also  produced 
when  potassium  cyanid  slowly  oxidizes  in  the  air. 

THIOCYANIC  ACID,  H— S— C=N,  sometimes 
called  sidjocyanic,  is  ol^tained  in  the  form  of  its  salts 
by  heating  alkali  cyanids  with  sulfur: 

KCN   +   S    =    KS— CN. 

potassium 
thiocyanate 

Ammotiiiim    thiocyanate    is    obtained    by    heating 


HYDROXYLAMIN.  379 

carbon  disulfid  with  ammonia  in  an  alcoholic  solu- 
tion : 

CS2  +  4NH3  =  NH.CNS  +   (NHJ.S. 


Besides  thiocyanic  acid,  we  have  the  isothiocyanic 
acid,  which  has  the  formula  H.N  =  C  =  S;  the  best 
known  compound  of  this  is  allyl  isothiocyanate,  a 
constituent  of  volatile  oil  of  mustard  (oleum  sinapis 
volatile),  which  should  contain  not  less  than  92% 
of  it. 

SODIUM  NITROPRUSSID,  Na2Fe(CN)5N0.2H20, 
is  a  valuable  reagent  for  detecting  sulfids,  with  which 
it  gives  an  intense  violet  color.  It  is  prepared  by 
acting  with  nitric  acid  on  potassium  ferrocyanid.  It 
crystallizes  in  ruby-red  prisms,  soluble  in  water. 

MERCURIC  THIOCYANATE,  Hg(CNS)2 
is  obtained  by  adding  mercuric  chlorid  to  a  solution  of 
potassium  thiocyanate.  Insoluble  powder  separates 
which,  on  drying,  takes  fire  on  ignition,  and  in- 
tumesces  with  voluminous  ash,  aggregating  in  long 
snake-like  tubes — "Pharaoh's  serpents."  The  vapor, 
containing  mercury,  is  poisonous. 

HYDROXYLAMIN,  NH^OH,  is  obtained  by 
reducing  ethyl  nitrate  with  hydrochloric  acid  and  tin; 
thus: 

(i)   2Sn,  +  8HCl  =  4SnCl2+   4H., 

hydrogen 

(2)   C2H5N03-h3H2  =  NH20H  +  C2H50H  +  H20. 
Two  forms  of  alkvl  derivatives  of  hvdroxvlamin  are 


380  PHARMACEUTIC    CHEMISTRY. 

known:    amethyl     hydroxylamin,    NHjOCHg,    and 
/3  methyl  hydroxylamin,  CH3.  NHOH. 

Hydroxylamin  is  a  valuable  reagent  with  the 
aldehyds  and  ketones,  with  which  it  forms  oximes, 
by  splitting  off  water;  thus: 

CH3^HO  +    NH.OH        =CH3X:jH  =  NOH  +HjO 
acetaldehyd  +  hydroxylamin     =      acetaldoxime 

It  will  be  observed  that  the  oxime  is  named  after 
the  aldehyd  employed;  thus,  from  acetaldehyd  we 
obtained  acetaldoxime;  likewise,  oximes  of  the 
ketones  are  named  after  the  parent  ketone.  Acetone 
with  hydroxylamin  gives: 

CH3.CQ.CH3    +^H,Oi^= 

acetone        +        hydroxylamin  = 

JCHj^jCNOH   +  H2O 

acetoxime 

The  oximes  are  sometimes  named  iso-nitroso  com- 
pounds. 

NH2 

HYDRAZIN,  I  ,  is  a  double  ammonia;  its 
NH2 
compounds,  especially  phenyl  hydra  zin,  CgH^NH.- 
NHj,  also  called  hydrazin-benzene,  i§  a  valuable 
reagent  in  organic  chemistry,  especially  in  the 
examination  of  sugars,  with  which  it  forms  two  well- 
defined  classes  of  compounds — the  hydrazones  and 
osazones. 

THE  DERIVATIVES  OF  SULFUR. 

MERCAPTANS  or  suljur  nhohols. 

Preparation. — The    mercaptans    are    formed    by 


PROPERTIES  OF  MERCAPTANS.        38 1 

treating  alkyl  halids  with  potassium  hydrogen  sulfid; 
thus: 

CH3I    +KSH   =   CH^SH^   KI 

methyl-mercaptan 

C^HjBr   +   KSH    =   QH^^H^   KBr. 

ethyl -mercaptan 

Properties. — Ethyl  mercaptan  is  the  most  common 
of  the  class.  They  are  mostly  liquids  of  a  dis- 
agreeable, garlicky  odor.  Similarly  with  alcohols, 
mercaptans  contain  a  hydrogen  atom  replaceable  by 
metals;  thus,  we  have  with  sodium,  a  compound, 
CHgSNa;  with  mercury,  (C2H5S)2Hg,  etc.  These 
compounds  are  known  as  mercaptids;  thus,  sodium 
methyl  mercaptid,  mercury  ethyl  mercaptid,  etc. 

When  subjected  to  oxidation,  mercaptans  differ 
from  the  alcohols  in  that  they  take  up  three  molecules 
of  oxygen,  forming  sulfonic  acids: 

C2H5SH  +  03  =  QHs.SOaOH. 

ethyl  sulfonic  acid 

The  structure  of  the  sulfonic  acids  may  be  written — 
/R  /CH3 

SO2       ;  thus,  SO,         is  methyl  sulfonic  acid. 

\OH  \6h 

/OH 
THIOCARBONIC  ACID,  CO      —  dithiocarbonic, 

\SH 

/SH 
also  called  xanthogenic  acid,  CO    ,  and  trithiocarhonic 
\SH 
/SH 
acid  CS       are  also  known 
\SH 


382  PHARMACEUTIC    CHEMISTRY. 

SULFUR  ETHERS.— The  allyl  sulfid  (a  constit- 
uent of  oil  of  garlic),  (C3H5),S,  mentioned  elsewhere 
is  a  type  of  sulfur  ethers.  They  all  possess  a  garlicky 
odor  and  all  are  prepared  by  acting  on  potassium 
sulfid  with  alkyl  halids. 


CHAPTER  XXX. 

SUBSTITUTION  PRODUCTS  OF  THE  ACIDS. 

ACID  AMIDS  are  prepared  by  heating  ammonium 
salts  of  the  corresponding  monobasic  organic  acids 
in  hermetically  sealed  tubes: 

CH3COONH,    =   CH3CO.NH3    +   H.O. 

ammonium  acetate     =  acetamid 

Each  molecule  of  the  salt  loses  a  molecule  of  water. 
The  amids  are  named  after  the  acids  contained  in  the 
salt;  thus,  from  ammonium  acetate  acel-amid  is  pro- 
duced; from  ammonium  propionate,  propion-amid, 
etc. 

(2)  The  amids  may  also  be  formed  by  acting  with 
strong  ammonia  solution  on  the  acid  chlorids: 

CH3.CO.CI   +    NH3   =  CH3.CO.  NH2   +  HCl. 

acetyl  chlorid 

(3)  Also  by  acting  with  strong  ammonia  on  the 
esters: 

CH3.CO.OC2H5  +  NH3  =CH3.CO.NH2  +  C3H50H. 

It  will  be  observed  that  the  amids  are  organic  acids 
in  which  the  hydroxyl  group  is  replaced  by  the  amido, 
NH2,  group: 

CH3.CO.OH         —         CH3.CO.NHa. 

acid  amid 

Properties. — .Acetamid    is    prepared    by    distilling 
ammonium  acetate  in  a  current  of  dry  ammonia.     It 
383 


384  PHARMACEUTIC    CHEMISTRY. 

is  a  colorless,  crystalline  compound,  melting  at  80°  C, 
possessing  the  unpleasant  odor  of  mice  urine;  it  is 
soluble  in  water;  when  boiled  with  acids  or  alkalis, 
it  hydrolyzes  into  acetic  acid  and  ammonia: 

CH3CO.NH2  +  HjO  -  CH3COOH  +  NH3. 

When  heated  with  phosphorus  pentoxid,  acetamid 
is  converted  into  methyl  cyanid  (acetonitrfl) : 

CH3.CO.NH2      —      H2O        =        CHg.C^N. 

aceto-nitril 

AMINO  ACIDS  are  obtained  by  treating  organic 
chloracids  with  strong  ammonia  solution: 

CH,ClCOOH+2NH3=CH.,.NH3.COONH,+HCl. 

mono-chlor  (glycin-ammonia) 

acetic  acid 

Glycocol  is  the  weakest  acid  of  the  amino  group, 
and  is  obtained  by  boiling  glycin-ammonia  with 
copper  carbonate,  when  a  crystalline  copper  salt  is 
obtained.  This  copper  salt  is  decomposed  by 
hydrogen  sulfid.  Cupric  sulfid  is  filtered  out,  and 
the  glycin  is  obtained  by  crystallization. 

AMINOACETIC  ACID,  ciNH^.COOH,  it  will  be 
observed,  is  acetic  acid,  in  which  one- of  the  hydro- 
gens of  the  hydrocarbon  has  been  replaced  by  the 
— NH2  group.  It  is  commonly  known  as  glycin,  a 
crystalline  substance,  melting  at  235  °  C.  The  amino- 
acids  are  of  interest  because  they  are  frequently 
found  among  the  decomposition  products  of  the 
proteids;  thus: 

Benzoyl  glycin,  "hip])uric  acid,"  is  found  in  llii' 
urine    of     horbivora.     \Mu'n     heated     with     strong 


HipPURic  acid;  leucin.  385 

hydrochloric  acid,  benzoic  acid  and  glycin  are  pro- 
duced; thus: 

CH,.NH[C0.C,H5  +  HO]H  =  CH^NH^    + 

I     '  I      '  • 

CO.OH CQ.QH 

hippuric  acid  glycin 

QH^.^OOH. 

benzoic  acid 

The  above  is  the  commercial  method  for  producing 
benzoic  acid. 

Methyl  glycin,  "sarcosin,"  is  obtained  by  boiling 
creatin  with  barium  hydroxid — or,  synthetically,  by 
condensing  methylamin  with  monochloracetic  acid: 

//CH3  H— N— CH3 

N— H    +   CH,C1    =     I 

\H  I     "  CH2  +  HCl. 

methylamin      COOH  | 

COOH 

sarcosin 

(C3H,0,) 
Creatin,  found  in  meat-juice  with  sarcoJactic  acid, 
is,     chemically,     "methyl     guanidin-acetic     acid," 

Betain,  "trimethyl  glycin,"  HO.(CH3)3N.CH2.- 
COOH,  is  found  in  molasses  prepared  from  beets. 

Creatinin,  C4H7N3O2,  is  the  anhydrid  of  creatin, 
found  in  small  quantities  in  urine. 

Alanin,  a-aminopropionic  acid,  CH3.CH(NH2)- 
COOH,  is  a  product  of  the  decomposition  of  silk. 

Leucin,    a-amino    isobutyl    acetic    acid,   (CH3)2.- 
CH.CH2.CH(NH2).COOH,    a    product   of    decom- 
position  of  glue  and  other  albuminoid   bodies,   is 
obtained  from  caproic  acid. 
25 


386  PHARMACEUTIC    CHEMISTRY. 

AMINS  are  strongly  basic  bodies  derived  from 
ammonia,  NH^,  by  substituting  the  hydrogen  atoms 
with  alkvl  grouj)s;  thus: 

.    ■  /CH3  /CH3  /CH3 

NH.  -^    N— H       —    N— CH3  --    N— CH3 

\H _„\Ji XCHa 

amin  methylamin  dimethylamin      trimethylamin 

(primary  amin)      (secondary  amin)   (tertiary  amin) 

Thus,  by  substituting  one  hydrogen  atom  in 
ammonia,  NH3,  a  primary  amin  is  obtained;  by 
substituting  two  hydrogens,  a  secondary  amin,  and 
by  substituting  all  three  hydrogens,  a  tertiary  amin. 
We  have,  therefore,  three  classes  of  amins:  the 
primary,  containing  the  characteristic  group — NH,; 
secondary,  containing  the  group  =  NH,  and  tertiary, 
containing  the  group  EEN. 

Preparation. — Amins  may  be  prepared: 
(i)  By  treating  alkyl  halids  with  ammonia: 
CH3Br  +  NH3==NH3CH3Br; 

methyl  ammonium 
bromid 

this  is  decomposed  by  distilling  with  alkali-hydroxid: 
NH3CH3Br  +  KOH  =  CH3.NH^+  KBr  +  H.O. 

methylamin 

Methylamin  is  the  simplest  member  of  the  class 
0/  alkaloids. 

(2)  By  reducing  corresponding  nitro-compounds 
by  nascent  hydrogen: 

CH3NO2  +  3H,  =  CH3.NH,  +  2H,(). 
Dimethylamin     is   obtained    l)y    treating    methyl- 
amin with  an  alkyl  halid: 

CH3NH2  +  CH3Br  =  (CH3).,:NH  +  HBr. 

dimethylamin 


PROPERTIES  OF  THE  AMINS.         387 

Trimethylamin  may  be  obtained  from  dimethyl- 
amin  by  treating  it  with  a  methyl  halid : 

(CH3)2NH  +  CHgBr  =  (CH3)3=N  +  HBr. 

trimethylamin 

The  =NH  group  of  the  secondary  amins  is  also 
called  "imido"  group,  and  secondary  amins  imido 
compounds. 

(3)  By  reducing  nitrils: 

C,H,.CN  +  2H.,  =  C2H,.CH..NH2. 

propionitril  propylamin 

Properties. — Amins  usually  possess  strong  ammoni- 
acal  odor,  strong  alkalin  reaction,  and  are  usually 
soluble  in  water;  they  precipitate  metals  from  their 
solutions,  and  with  acids  they  form  addition  products; 
in  these  last  two  properties  they  are  similar  to 
ammonia;  thus:  like 

HNOj 

NH3     +     HCl       =      NH3HCI 

H2SO4 

NH3HNO3 '  (NH3)2H2SO, 

HNO3 
CH3NH.>+HC1       =      CH3NH2HCI— — ^ 

methylamin  m.  hydrochlorid 

H2SO4 

CH3NH.>HN03 .    (CH3NH,)3H3SQ, 

m.  nitrate  m.  sulfate 

Identification. — (i)  The  primary  amins  with  ni- 
trous acid  lose  the  amido  group  which  is  replaced 
by  the  hydroxyl  group: 

CH3NH,  +  HNO2  =  NH3.CH3.NO, 

intermediate  com- 
pound 

which  is  hydrolyzed: 

NH3.CH3.NO2  =  CH3OH.  +  N,  +  HjO. 


388  PHARMACEUTIC    CHEMISTRY. 

(The  above  is  a  method  of  diazotization,  whereby 
an  — OH  group  can  be  introduced  in  a  compound.) 

(2)  The  seoeniary  amins,  when  heated  with 
alcoholic  potash  and  chloroform,  give  the  isonitril 
reaction  (p.  377). 

(3)  The  tertiary  amins  combine  directly  with 
alkyl  halids: 

(CH,)3EEN    +    CHJ      =     N(CH3)J. 

tetramethyl    am- 
monium iodid 

Neither  of  the  other  classes  of  amins  afford  the 
reactions  given  under  each  class,  and  these  serve, 
therefore,  as  means  of  identification. 

Amins  of  all  three  classes  have  the  property  of 
forming  double  compounds  with  platinum  chlorid 
analogous  to  the  similar  compounds  with  ammonium 
and  potassium.  This  property  is  made  use  of  in 
quantitatively  identifying  an  amin.  Thus,  methyl- 
aminplatinumchlorid,  (CH3NH,)2.PtCl6,  when  ig- 
nited, yields  41.5%  of  metallic  platinum. 

COMPOUNDS  ANALOGOUS  TO  THE  AMINS. 

These  compounds  show  the  close  chemical  rela- 
tionships between  nitrogen,  phosphorus,  antimony 
and  arsenic.  They  are  known  as  PHOSPHIN  or 
phosphonium,  PH^,  STIBIN  or  stibonium,  SbHg,  and 
ARSIN  or  arsonium,  AsHg.  They  may  be  regarded 
as  derivatives  of  ordinary  phosphin  or  arsin,  etc., 
and,  like  the  amins,  may  be  primary,  secondary  or 
tertiary: 

PH.,    —    12l2<^H:.     -^     I'HjCHa),    —    P(CH3), 

phosphin  methyl  dimethyl  trimethyl 

phosphin  phosphin  phosphin 


ORGANO-METALLIC    COMPOUNDS.  389 

Quaternary  phosphonium  iodids  and  hydroxids 
have  likewise  been  isolated: 

(CH3),P.I  (CH3).P-OH 

tetramethyl  phosphonium  tetramethyl  phosphonium 

iodid  hydroxid. 

Preparation. — By  the  action  of  alkyl  iodids  on 
phosphin,  etc.: 

CH3I  +  PH3  =  PH2.CH3  +  HI. 

From  the  primary,  a  secondary,  and  from  this 
tertiary  phosphin  may  be  obtained  similarly  with 
the  amins.     All  the  phosphins  are  inflammable. 

There  are  no  primary  or  secondary  arsins  known ; 
the  tertiary  arsins,  (CH3)3As,  and  quaternary 
arsonium  iodids  and  hydroxids  are  well-known: 
(CH3),As.I  and  (CH3),As.OH. 

CACODYL  is  obtained  by  distilling  a  mixture  of 
equal  parts  of  arsenous  oxid  and  potassium  acetate. 

Cacodyl  was  first  obtained  by  Cadet  in  1760,  and 
is  contained  in  "Cadet's  liquid."  Its  composition 
was  ascertained  by  Bunsen  (1837),  who  named  it 
cacodyl  (from  kakodus,  stinking)  in  reference  to 
its  intolerable  smell.  It  is  exceedingly  poisonous, 
inflammable  and  has  the  formula  As2(CH3)4. 

TRIMETHYL  STIBIN  has  the  formula  (CH3)3Sb, 
and  tetramethyl  stibonium  hydroxid, — (CH3)^Sb.0H, 
both  are  known,  but  both  are  unimportant. 

ORGANO-METALLIC  COMPOUNDS.— This  term 
is  applied  to  alkyl  compounds  of  the  metals.  They 
resemble  nonmetal-alkyl  compounds,  both  in  prop- 
erties and  in  the  method  of  production. 


390  PHARMACEUTIC    CHEMISTRY. 

ZINC  ALKYLS.— Frankland  synthetised  paraffins 
(1849)  l->^'  treating  alkvl  halids  with  metallic  zinc: 
2CH3I    +   Zn    =    C,H«    +   Znl,. 

ethane 

He   observed,  however,  that  an  additional  com- 
pound was  formed  when  the  zinc  was  in  excess: 

/CH, 
CH3I    +   Zn    =.  Zn^ 

^I  . 

zinc  methyl  iodid. 

When  this  compound  is  distilled,  zinc  methyl  is 
formed : 

/CH3 
2Zn('  =     Zn(CH3),      +   Znl, 

^  I  zinc  methyl 

When  halogens  act  on  zinc  methyl  alkyl  halids 
are  formed: 

Zn(CH3)2  +  2I2  =  Znl,  +  2CH3I. 

Similarly  to  zinc  methyl,  we  obtain: 

Hg(CH3)2  =  methyl  mercury; 

Bi(CH3)3  =  methyl  bismuth,  and 

Sn(CH3),  =  methyl  tin.  etc. 

These  compounds  are  very  inflammable  and 
volatile. 

URIC  ACID  AND  ITS  DERIVATIVES. 

URIC  ACID,  C5H4N4O3,  is  closely  related  to  urea, 
both  physiologically  and  chemically.  It  is  almost 
the  chief  nitrogenous  secretion  in  many  animals,- 
birds  and  reptiles.  In  human  urine  it  constitutes 
in  quantity  about  one-si.\tieth  that  of  urea  secreted 
under  normal  conditions.  Uric  acid  forms  three 
classes  of  salts — neutral,  acid  and  hyperacid  urates. 


STRUCTURE    OF    URIC   ACID.  39 1 

Of  the  alkali  urates  only  the  potassium  and  lithium 
salts  are  soluble.  Lithium  urate  is  the  most  soluble, 
while  ammonium  urate  is  insoluble. 

Formation  and  Structure. — Uric  acid,  chemically, 
is  the  diureid  of  trioxyacryllic  acid: 
COOH 

CO  +      II      OH       +  CO 

\nh.       c/  nh.X 

urea    '  ^OH  "^^^^ 

trioxy-acryl- 
lic  acid 

NH— CO 

!        I 

_       CO      C— NH\ 
■    -        I  II  >CO+H.O 

NH— C— NH/ 
uric  acid 

It  may  be  made  artificially  by  heating  urea  with 
cyanacetic  acid. 

When  uric  acid  (or  a  little  evaporated  urine)  is 
covered  with  a  drop  of  nitric  acid,  evaporated  to 
dryness,  upon  the  addition  of  a  drop  of  ammonia,  a 
beautiful,  purplish  color  (murexide)  is  developed. 
Xanthin  and  guanin  produce  the  same  reaction,  but 
on  the  addition  of  a  drop  of  sodium  hydrcxid  the  red 
color  turns  to  blue  (distinction  from  xanthin,  etc.). 

Concentrated  solutions  of  uric  acid  reduce  Fehling 
solution. 

PARABANIC  ACID  is  "oxalyl  urea,"  produced 
from  oxalic  acid,  urea  and  phosphorus  trichlorid.     It 

/NH.CO 
has  the  formula  CO  | 

\NH.CO. 


392  PHARMACEUTIC    CHEMISTRY. 

BARBITURIC  ACID  is  prepared  hy  the  same  re- 
action from  malonic  acid,  CH^C^  ^qut^  /CO;  the 

hydroxvl  barbituric  acid  is 

CONH 
DIALURIC  ACID,  CH()H(^  ^CO;  and 

ALLOXAN  is  dihydroxybarbituric  acid, 
rOHN 
C(OH).,(^  ^CO. 

It  is  prepared  from  uric  acid  l^y  oxidizing  it  with 
nitric  acid: 

C5H^N,03  -f  H,0+0    =   C4H,N.O,  +  CO(NH,), 
uric  acid.  alloxan  urea 

XANTHIN,  CjH.N.O,,  is  closely  related  to  uric 
acid. 

Occurrence. — In  both  the  vegetable  and  animal 
kingdoms,  in  lupine  seeds,  malt,  tea,  in  meat-juices, 
etc. 

While  it  contains  one  oxygen  less  than  uric  acid 
on  oxidation,  it  yields  the  same  products — alloxan 
and  urea. 

GUANIN,  C5H5N5O,  is  obtained  from  guano  by 
extracting  it  with  hot  milk  of  lime,  then  with  sodium 
carbonate,  which  extracts  the  guanin.  The  product 
is  next  precipitated  with  acetic  acid  and  crystallized 
from  hot  dilute  hydrochloric  acid.  Guanin,  in 
structure,  is  related  to  xanthin,  into  which  it  is 
converted  with  nitrous  acid.  When  oxidized,  guanin 
gives  guanidin  (CNjHg)  and  oxalyl  urea. 


THEOBROMIN,    CAFFEIN   AND    THEIN.  393 

THEOBROMIN,  CyHgN^Oa,  has  been  synthetized 
from  xanthin.  Chemically,  it  is  diwethylxanthin. 
Found  in  cacao-beans  to  the  extent  of  2%. 

CAFFEIN  and  THEIN,  CgHjoN^Oj,  are  present  in 
coffee  and  tea,  after  which  they  have  been  named. 
Cofifee  beans  contain  1%  of  caflfein,  tea  leaves  from 
1-5  to  3%  of  thein;  these  bodies  are  identical  and 
usually  classed  among  the  alkaloids.  Chemically, 
triniethylxanthins.  The  relationships  of  the  forego- 
ing compounds  may  be  shown  by  their  structure: 

NH— CO  NH— CO 

II                               II 
C=0  C— NH\  C=0  C NH  — 

nh-c-nhX           jIh-C-N^^'' 
uric  acid  ^^^^^^ 

NH— CO  (CHON CO 

II  "II 

C=0  C— N(CH3)   —  C=0  C— N(CH3) 

I  II       >H  I  II         >H. 

(CH3)— N C— n/"  (CH3)N C— N./ 

dimethyl  xanthin  trimethyl  xanthin 

(theobromin)  (caffein  (thein) 


CHAPTER  XXXI 
THE  CARBOHYDRATES. 


Monosaccharoses 


Disaccharoses  Polysaccharoses 


(C6H,,06,: 


(C,.H,,0„.) 


+  Glucose,      grape-  +  Cane-sugar, 
sugar,  or  dextrose  i        saccharose 

—  Fructose,       fruit-  j  -J-  Milk-sugar, 
sugar,  or  levulose  :        lactose 

-f  Galactose  -f  Malt-sugar, 
-|-  Mannose  maltose 

—  Sorbinose 


(C6H,o05)n, 
+  Starch 
-}-  Cellulose 
—  Inulin 
+  Glycogen 
-|-  Dextrin 
The  gums 


Trisaccharose, 

C,8H„Ox6, 

-|-  Raffinose,  or  Melitriose 


The  term  "carbohydrate,"  or  carbhydrjte,  is 
applied  to  a  group  of  natural  substances,  which,  in 
addition  to  carbon,  contain  also  hydrogen  and 
oxygen  in  the  proportion  in  which  these  unite  to 
form  water. 

Cane-sugar,  CjjHjjOu;  glucose,  CgHisOe,  and 
starch,  (CgHioOs)^,  are  the  familiar  carbohydrates. 

The  carbohydrates  are  closely  related;  all  the 
members  of  the  group  are  alcohols,  some,  in  addi- 

Note. — The  algebraic  signs  preceding  each  name  refer  to 
the  character  of  the  optical  rotation;  thus,  the  minus  ( — ) 
sign  indicates  levo-(left-handed)  rotary,  and  plus  (+)  sign 
the  dextro-(right-handed)  rotary  sugars. 


,SQ4 


ALDOSES  AND  KETOSES.  395 

tion,  containing  aldehyd  and  ketone  groups.  Sub- 
stances which  give  reactions  of  two  classes  of  sub- 
stances are  termed  "tautomeric." 

Carbohydrates  containing  the  aldehyd  group  are 
termed  aldoses;  those  containing  the  ketone  group, 
ketoses. 

The    simplest    "  liydroxyaldehyd,''    or    aldose,  is 
CH.(CH) 
glycollic   aldehvd,     \  ;  the  second,  glyceric 

CHO 
CH^COH) 

aldehyd  CII(OH),  etc.     Correspondingly,  the  lowest 

CHO 

"hydroxyketone,"  or  ketose,  is  dioxyacetone, 
CH^COH) 

C=0 

I 
CH2(0H). 

These  are  regarded  as  oxidation  products  of 
polyatomic  alcohols.  Their  nomenclature  consists  in 
the  termination  "ose,"  and  a  Greek  numeral  prefix 
indicating  the  number  of  carbon  atoms  in  the  mole- 
cule. The  -above-named  carbohydrates  may  serve 
as  examples: 

CH2OH  CH.(OH) 

CH,OH  I  I 

I     "          —    CHOH  —       C  =  0 
CHO  1  I 

aldo-biose  CHO  CH^O-H 


396  PHARMACEUTIC    CHEMISTRY. 

The  necessity  for  this  system  is  apparent  with  the 
higher  members  which  are  isomeric;  thus,  there  are 
four  possible  aldo-tetroses,  eight  aldo-pentoses, 
sixteen  aldo-hexoses;  besides,  there  are  heptoses, 
octoses,  etc.,  besides  the  isomeric  ketoses. 

The  carbohydrates  are  among  the  chief  products 
of  plant  life,  and  to  a  small  extent  also  of  animal 
life.  We  have  mentioned  the  familiar  examples,  as 
sugar,  starch,  etc.,  from  the  vegetable  kingdom; 
equally  important,  however,  are  milk-sugar,  glycogen 
and  frequently  grape-sugar  derived  from  the  animal 
organism. 

The  extensive  distribution  of  the  carbohydrates, 
their  extensive  use  as  foods,  as  materials  for  the 
fermentation,  fabric,  paper  and  many  other  indus- 
tries, makes  them  very  important  and  interesting. 

Classification. — Carbohydrates  are  naturally  di- 
vided into  those,  like  sugar,  sweet  and  soluble,  and 
into  the  tasteless  and  insoluble.  The  sugars  are 
further  divided  into  the  monosaccharids,  containing 
6  carbons;  disaccharids,  with  12  carbons,  and 
trisaccharids,  with  18  carbons  in  the  molecule. 
Their  empiric  formula  is  written  (CeHioOj)^. 

For  the  important  sugars,  examine  the  table  at 
the  head  of  this  article. 

MONOSACCHAROSES  are  strong  reducers,  sepa- 
rating silver  from  silver  nitrate  ammonia  solution, 
also  reducing  Fehling's  solution,  in  this  respect  act- 
ing as  aldehyds.  With  hydrocyanic  acid  they  form 
cvanhydrin  ,  with  phenylhydrazin  they  form  hydra- 
zones  which,  upon  treatment  with  another  molecule 


397 


of  phenylhydrazin,  are  converted  into  phenyl- 
hydrozone  of  glucozone,  this,  with  another  molecule 
of  the  reagent,  gives  osazone;  thus: 

(i)  CH2OH  CH2OH 

(CH.OH),  (CH.0H),+H20 

CH   ib+H,;  N^NELC„H3=  CH:N.NH.C«H5 


glucose 


phenyl 
hydrazin 


glucose  phenyl 
hydrazone 


(2)  CH2OH 

CHOH 

I 
CHOH 

I 
CHOH 

I 
CHOH  +  NHj.NH.CeH, 

I 

CHrN.NH.CeH, 

glucose  phenylhy- 

drazone 


CH.OH 

I 

CHOH 

I 
CHOH 

I 
=  CHOH 

I 

C  =  0    +NH3+NH,.C6H, 
I  anilin 

CH.N.NH.CeH.; 
glucozone 


It  will  be  seen  that  the  second  molecule  of  the 
reagent  has  converted  the  first  compound  into  a 
ketone  ; 


(3)  CH.OH 


CHOH 

i 
CHOH 

I 
CHOH 

I 
C  = 


O  +  H, 


N.NH.CeH, 


CH:N-NH.C6H, 

glucozone 


CH2OH 

CHOH 

I 
CHOH 

I 
CHOH 

I 
C=N.NH.C6H5+H,0 

CHiN.NH.CeH^ 

phenylglucosazone. 
(osazone) 


398  PHARMACEUTIC    CHEMISTRY. 

The  osazones  are  nearly  insoluble  in  water,  well- 
defined  crystals  which  separate  from  a  solution  con- 
taining the  sugar.  They  can  be  readily  recognized 
under  the  microscope  and  have  a  regular  definite 
melting-point  by  the  use  of  this  reagent,  it  was  pos- 
sible for  Fischer  (1887  to  1890)  to  identify,  separate 
and  synthetizo  a  number  of  new  sugars. 

With  hydroxylamin,  the  monosaccharoses  give 
flximes,  they  are  readily  oxidized,  yielding  mono-  and 
dibasic  acids  in  the  case  of  aldoses,  while  the  ketoses 
break  up  into  acids  containing  fewer  carbon  atoms. 
When  warmed  with  nitric  acid,  they  are  all  con- 
verted into  oxalic  acid,  and  with  hydrochloric  into 
levulinic  acids.  They  are  directly  jermentable  with 
yeast. 

DEXTROSE,  grape-sugar  or  glucose,  CHjOH.- 
(CHOH)^.CHO,  occurs  naturally  in  many  fruits  and 
sweet  plants,  either  alone  or  associated  with  levulose. 
It  has  been  named  "dextrose"  in  that  it  rotates 
polarized  light  to  the  right,  and  "grape-sugar" 
because  it  is  found  in  ripe  grapes.  Grape-sugar 
may  be  artificially  made  by  hydrolyzing  cane-sugar 
with  dilute  h\drochIoric  acid: 

C..H,,0„  -I-  H^O  =     C6H..06    -f   C6H..06 
sugar  dextrose  levulose 


The  mixture  of  dextrose  and  levulose  is  known  as 
"invert  sugar,"  and  from  this  grape-sugar  may  be 
obtained  by  crystallizing  from  hot  aUohol  in  whicii 
levulose  is  soluble. 

This  inversion  of  the  disaccharoses  mav  also   be 


LEVULOSE   AND    GALACTOSE.  399 

brought  about  by  hydrolytic  enzymes,  invertase  and 
maltase. 

Dextrose  melts  at  86°  C,  is  soluble  in  water, 
insoluble  in  absolute  alcohol.  The  specific  rotation 
[a]D   =    +   52.5. 

LEVULOSE,  jntdose,  CH20H.(CHOH)3.CO.- 
CHjOH,  occurs  naturally  in  honey  and  in  ripe  fruits, 
and  is  produced  together  with  grape-sugar  by  hydro- 
lyzing  cane-sugar.  It  is  best  prepared  from  inulin 
by  hydrolyzing  it  with  dilute  acids.  It  may  be 
isolated  from  this  by  boiling  with  alcohol  from  which 
levulose  separates  in  small  granular  crystals.  It  melts 
at  96°  C,  has  the  specific  rotation  [(7]D  =  — 93°. 

Levulose  is  soluble  in  water  and  alcohol,  directly 
fermentable  with  yeast,  forming  alcohol  and  carbon 
dioxid;  it  reduces  Fehling's  solution.  When  oxid- 
ized, it  yields  trihydroxybutyric  and  glycollic  acids, 
each  containing  fewer  carbon  atoms  than  the  original 
sugar,  thus  proving  that  it  contains  the  ketonic  group: 

CH.OH 
C6Hi,06-f02  =  CH,OH.CHOH.CHOH.COOH+     | 

trihydroxybutric  acid  COOH 

glycollic 
acid. 

With  phenylhydrazin,  it  produces  phenylglu- 
cosazone,  and  with  hydroxylamin,  an  oxime. 

GALACTOSE,  CeHijOg,  is  produced  together  with 
dextrose  by  hydrolyzing  milk-sugar  (lactose).  Ga- 
lactose reduces  Fehling's  solution,  ferments  with 
yeast,  with  phenylhydrazin  it  gives  galactosazon, 
melting  at  193°  C. 


400  PHARMACEUTIC    CHEMISTRY. 

Galactose  crystallizes  in  fine  needles,  melting  at 
163°  C. 

DISACCHAROSES.  -  CANE  SUGAR,  sucrose, 
C,2H220ji,  is  found  naturally  in  the  sugar-cane,  beet, 
maple  and  various  other  plants. 

Preparation. — By  expressing  the  juice  from  the 
respective  plants,  neutralizing  with  lime  to  remove 
impurities  and  to  prevent  inversion  by  the  plant- 
acids.  The  lime  is  removed  by  passing  COj  into 
the  liquid,  as  calcium  carbonate;  the  liquid  is  next 
evaporated  in  vacuo  until  crystallization  occurs. 
The  crude  sugar  is  redissolved,  filtered  through 
bone-black  to  decolorize  it,  evaporated  and  recrystal- 
lized.  The  mother  liquor,  or  "residual  sugar- 
house  syrup,"  is  sold  as  molasses. 

Sugar  (saccharum)  is  soluble  in  water  (one-half 
its  own  weight),  sparingly  in  alcohol.  It  melts  at 
160°  C,  at  higher  temperatures  it  darkens,  and 
finally  carbonizes  into  a  dark  brown  syrup,  known 
as  burnt  sugar  or  "caramel." 

Sucrose  has  the  specific  rotation  [a]  D  =  -H  66.5°; 
the  rotary  power  of  sugar  is  made  use  of  in  deter- 
mining its  sucrose  content. 

Sucrose  is  not  directly  jerwcntahle  with  yeast,  but 
after  inverting  with  dilute  acids  into  glucose, 

QH,/),,  -f-  H2O  =  aCgHioOe, 
it  ferments  into  alcohol  and  carbon  dioxid. 

Sucrose  does  not  reduce  Fehling's  solution,  nor 
does  it  react  with  phenyihydrazin  or  hydroxylamin. 
showing  that  it  contains  neither  the  aldehydic  nor 
ketonic  group. 


LACTOSE,    MALTOSE,    RAFFINOSE.  401 

LACTOSE,  milk  sugar,  C12H22O11.H2O,  is  a  natural 
constituent  of  milk. 

Preparation. — By  removing  the  curd  from  milk 
by  means  of  rennet,  evaporating  the  "whey," 
filtering  through  bone-black  and  crystallizing. 

Lactose  (saccharum  lactis)  is  harder  than  sucrose 
and  therefore  valued  for  its  attrition  properties  in  the 
preparation  of  triturations  of  energetic  drugs,  in  the 
making  of  tablets  and  pills.  Lactose  is  less  soluble 
than  sucrose  and  maltose,  it  has  the  rotation 
[a]  D  =  +  80°. 

Lactose  reduces  FehUng's  solution;  is  not  directly 
jermentahle  with  yeast;  it  reacts  with  phenylhydrazin. 
When  boiled  with  dilute  acids,  it  hydrolyzes  into 
dextrose  and  galactose.  When  sprinkled  upon 
strong  H2SO4,  it  should  not  immediately  darken 
(absence  of  sucrose). 

MALTOSE,  malt  sugar,  C12H22O11.H2O,  is  obtained 
from  the  "wort"  extracted  from  malt — "sprouted 
l)arley,"  and  produced  by  the  action  of  "diastase" 
upon  starch.  This  is  the  object  of  "malting" 
barley;  the  diastase  at  a  favorable  temperature 
hydrolyzes  the  starch  in  the  moist  grain  into  sugar. 

Maltose  crystallizes  in  small  white  crystals;  it  is 
very  soluble  in  water,  and  has  the  rotation 
[a]  D  =  +140° — It  is  directly  fermentable  with  yeast. 
It  reduces  Fehling's  solution;  with  phenylhydrazin 
it  forms  crystalline  phenylmaltosazon.  Its  other 
reactions  indicate  that  it  is  an  aldehydic  sugar. 

RAFFINOSE,  Ci8H320ifi  +  5H2O,  is  a  tasteless 
sugar  found  in  the  sugar-beet.  When  boiled  with 
26 


402  PHARMACEUTIC    CHEMISTRY. 

dilute  acids  it  hydrolyzes  into  glucose,  galactose 
and  levulose. 

POLYSACCHAROSES.— STARCH  (amylum)  is  a 
constituent  in  the  cells  of  many  plants,  it  is  usually 
stored  in  the  underground  stems,  as  potato,  or  in 
seed,  as  maize  or  wheat,  etc.  In  Europe,  starch  is 
mainly  prepared  from  potatoes;  in  America,  from 
maize,  and  in  India,  from  rice.  The  process  of 
starch-making  consists  in  grinding  the  tubers  or 
seeds,  washing  with  a  stream  of  cold  running  water, 
which,  holding  the  starch  grains  in  suspension,  is 
run  off  into  deposit  vats,  where  the  starch  deposits 
as  a  paste,  which  is  washed  and  dried. 

The  microscopic  appearance  of  the  different 
starches  is  such  as  to  determine  its  source,  this  is  a 
valuable  property  in  detecting  starches  in  powdered 
drugs,  of  which  they  are  frequent  adulterants. 

Starches  occur  in  a  white,  amorphous  ])owdcr, 
insoluble  in  water,  but  upon  boiling  the  granules 
swell  slightly,  burst  and  partially  dissolve.  The 
soluble  portion  is  called  granulose;  the  insoluble, 
starch  cellulose.  Starch  is  colored  blue  with  iodin. 
When  boiled  with  nitric  acid,  dextrin  (British  gum) 
is  produced.  De.xtrin  dissolves  in  water,  furnishing 
a  valuable  mucilage,  which  may  also  be  used  for 
saponification  purposes.  When  further  heated,  de.x- 
trin is  finally  converted  into  dextrose. 

The  constitution  of  starch  is  at  the  present  time 
unknown;  its  empiric  formula  is  usually  written 
(C,H,oO,0,, 

INULIN,  (C,.H,o()5).„  is  a  sul)stancc  replacing  the 


GLYCOGEN  AND    CELLULOSE.  403 

Starch  granule  in  the  cells  of  the  compositae.  It  is 
a  white  powder,  soluble  in  hot  water,  colored  yellow 
with  iodin,  and  when  hydrolyzed  with  dilute  acids 
it  is  converted  wholly  into  levulose. 

GLYCOGEN,  (C^U^^O^)^,  is  a  carbhydrate  occur- 
ring in  the  liver  of  mammals.  It  is  a  white  powder, 
soluble  in  boiling  water,  colored  brown  with  iodin; 
when  boiled  with  dilute  acids,  it  is  hydrolyzed 
into  dextrose,  while  with  diastase  it  becomes  a 
maltose. 

CELLULOSE,  (Ci2H2oOio)n,  is  the  principal  con- 
stituent of  the  cell-walls  of  plants.  While  the  cell 
walls  of  young  plants  consist  almost  entirely  of 
cellulose,  as  these  become  older  this  is  replaced  by 
lignin  and  such  other  material  as  wax,  gum,  etc. 

Pure  cellulose  (gossypium  purificatum)  can  be 
prepared  from  plant  fibers,  such  as  raw  cotton,  by 
washing  it  with  ether  to  remove  the  waxes;  next, 
with  alkali  carbonate  to  remove  gum;  then  with 
hydrochloric  acid  to  destroy  the  lignin,  and  finally 
with  weak  alkali  hydroxid  to  neutralize  the  acid. 

In  this  way  absorbent  cotton,  which  is  the  purest 
form  of  cellulose,  is  produced. 

Pure  cellulose  occurs  in  a  white  amorphous  mass, 
insoluble,  but  dissolved  by  ammoniacal  copper 
sulfate  solution,  from  which  it  may  be  reprecipitated 
in  the  form  of  a  gelatinous  mass  by  acids.  By  treat- 
ing cellulose  with  strong  sulfuric  acid,  a  semitrans- 
parent  mass  of  "vegetable  parchment"  is  obtained. 
By  dipping  paper  into  a  mixture  of  two  volumes 
sulfuric  and  one  volume  of  water,  the  paper  becomes 


404  PHARMACEUTIC    CHEMISTRY. 

tough  and  translucent.  \\'ashed  free  from  the  acid 
and  dried,  it  constitutes  parchment  paper. 

Strong  alkali  solutions  produce  gelatinization  and 
thickening  of  the  walls  of  vegetable  fiber,  followed 
by  contraction.  Advantage  is  taken  of  this  fact  in 
dipping  cotton  fiber  and  cloth,  in  that  it  produces 
crinkled  or  mercerized  surfaces. 

Nitric  acid  acts  upon  cellulose,  rapidly  pro- 
ducing a  series  of  cellulose  nitrates  known  as 
nitrocelluloses  or  pyroxylins.  These  substances 
are  not  true  nitrates,  but  rather  nitric  esters  of 
cellulose.     The  hexanitrate  is  known  as  gun-cotton. 

NITROCELLULOSE.— The  hexanitrate,  C.^Yi.^O,- 
(O.N02)6,  is  the  true,  highly  explosive  gun-cotton. 
It  is  prepared  by  macerating  pure  cotton  in  a  mixture 
of  3  parts  fuming  nitric  acid  and  i  part  strong 
sulfuric  acid  for  24  hours,  at  a  temperature  not 
exceeding  10°  C.  It  is  next  removed,  washed  free 
from  the  acid  and  carefully  dried  at  low  temperature. 
When  compressed  into  cartridges  it  can  be  detonated 
and  forms  a  powerful  explosive.  The  hexanitrate 
is  insoluble  in  a  mixture  of  ether-alcohol,  but  forms  a 
transparent  jelly.  This  jelly  with  nitroglycerin 
constitutes  the  powerful  explosive  cordite. 

The  hexanitrate  dissolved  in  nitroglycerin  con- 
stitutes blasting  gelatin. 

Soluble  gun-cotton,  C,2Hj608(N03)4,  pyroxylinum, 
Pyroxylin,  tetranitrocellulose,  consists  chiefly  of 
cellulose  tetranitrate  It  should  be  kept  in  cartons, 
protected  from  the  light.  A  yellowish-white,  matted 
mass  of  filaments,  resembling  raw  cotton.     Exceed- 


EXTRACTION  OF  VEGETABLE  DRUGS.     405 

ingly  inflammable,  burning  with  a  rapid,  luminous 
flame,  slowly  but  completely  soluble  in  25  parts  of  a 
mixture  of  alcohol  (i  vol.)  and  ether,  (3  vols.),  (collo- 
dion); also  in  acetone  (liquid  skin)  and  in  glacial 
acetic  acid;  and  precipitated  from  these  solutions  on 
addition  of  (NHJjS,  gives  raw,  artificial  silk.  Gun- 
cotton  is  prepared  from  cellulose  in  which  four  OH 
groups  have  been  replaced  by  four  NO3  groups; 
thus: 

2CeH,o05  +  4HNO3  =  Q3H,eOe(N03),  +  4^,0. 
This  is  the  official  or  "soluble  gun-cotton,"  while 
the  following: 

2CeH,o05  +  6HNO3  =C,,-ii,,0,{NO,),  +  6H2O 
constitutes  the  hexanitrate  which  is  the  true  explosive 
guncotton  described  above,  and  is  insoluble  in  the 
mixture  of  alcohol  and  ether.     From  pyroxylin  the 
collodion  of  the  Pharmacopoeia  is  prepared  {4%). 

CELLULOID,  xylonite,  is  a  substance  made  from 
pyroxylin  and  camphor  by  dissolving  the  former 
in  the  latter  by  fusion.  When  coloring  matter  is 
added,  delightful  tints  are  produced.  This  fused 
mass  is  pressed  powerfully  into  appropriate  moulds, 
furnishing  many  appurtenances  of  domestic  and 
industrial  utility. 

DEXTRIN  (British  gum).— Two  varieties  of  this 
substance  are  known — the  white  and  the  yellow. 
It  is  obtained  by  boiling  starch  with  water  acidulated 
with  sulfuric  or  nitric  acids.  Employed  as  a 
mucilage,  which  is  a  good  emulsifying  agent. 

EXTRACTION  OF  VEGETABLE  DRUGS.  Based 
on  the  Insolubility  oj  Cellulose. — A  very  important 


4o6  PHARMACEUTIC    CHEMISTRY. 

l)rinci])le  in  i)harmacy  is  attached  to  the  insolubilil)- 
of  cellulose  in  inorganic  solvents:  Cellulose  forms 
the  bulk  of  inert  plant-matter  and,  being  insoluble 
in  ordinary  solvents  (alcohol  and  water),  principles 
soluble  in  these  solvents  can  readily  be  separated 
from  it.  Solvents  used  for  the  extraction  of  proximate 
principles  (alkaloids,  glucosids,  resins,  oleoresins, 
organic  acids,  volatile  oils,  fixed  oils,  waxes,  coloring 
matters  and  various  aromatic  principles,  etc.)  are 
known  as  menstrua  (sing.,  menstruum). 

PAPER  (charta)  is  prepared  directly  from  cellulose 
in  the  form  of  wood,  straw  or  linen  rags  by  heating 
in  revolving  cylinders  with  alkalis,  steam  and,  under 
pressure,  beating  into  a  pulp  and  bleaching  with 
chlorin  gas.  The  pulp  is  transferred  to  endless 
felt-belting,  revolving  on  heated  cylinders  to  dry  and 
the  sheets  are  finally  pressed  between  hot  rollers  to 
give  them  a  smooth  or  "calendered"  surface. 
Paper  to  which  glue  or  talcum  has  been  added  to 
produce  a  gloss  and  high  finish  is  called  "sized." 
Paper  to  which  no  similar  substances  have  been 
added  is  called  "unsized"  paper,  and  is  the  kind 
directed  for  the  official  paper. 

SUBERIN  is  a  modification  of  cellulose  and  con- 
stitutes cork. 


CF 


CHAPTER  XXXII. 

CYCLIC    OR  AROMATIC    HYDROCARBONS  AND 
THEIR  DERIVATIVES. 

Also  called  carbocyclic,  or  closed-chain,  com- 
pounds, and  frequently  BENZENE  SERIES. 

When  coal-tar  is  subjected  to  destructive  distil- 
lation, the  distillate  produced  upon  standing  separates 
into  two  layers. 

The  upper  layer  is  a  dark  brown,  aqueous  liquid, 
containing  ammonia  and  ammonium  sulfid,  the 
lower  layer  consists  of  "coal-tar." 

When  the  coal-tar  is  in  turn  subjected  to  dis- 
tillation, two  fractions  are  obtained — the  volatile,  a 
brown,  oily  liquid,  and  a  residue  of  coal-tar  pitch, 
commonly  known  as  "asphaltum." 

When  asphaltum  is  further  distilled,  it  yields 
chrysene,  pyrene,  etc.  (commercially  not  valuable), 
and  a  residue  which  is  "coke." 

If,  now,  the  brown,  oily  liquid  be  subjected  to 
fractional  distillation,  it  can  be  separated  into  two 
portions,  one  of  which  floats  upon  water  and  is, 
therefore,  known  as  "light  oils,"  and  a  second 
fraction  possessing  a  higher  specific  gravity  than 
water  and  in  which  it  will  sink,  known  as  "heavy 
oils." 

The  "light  oils"  contain  three  different  classes  of 
compounds: 

407 


408  PHARMACEUTIC    CHEMISTRY. 

(i)  Hydrocarbons,  as  benzol,  toluol,  three  xylols, 
ethyl  benzene,  mesitylene,  pseiidociimene,  terpene, 
naphthalene  dihydrid,  diphenyl,  methyl  anthracene, 
also  hydrocyanic  and  acetic  acids. 

(2)  Oxygenated  substances  allied  to  the  alcohols, 
as  phenol,  ortho-,  meta-  and  imracresols,  xylenol, 
etc.;  and, 

(3)  Basic  compounds  similar  to  the  amins,  as 
pyridin,  pyrrol,  anilin,  quinolin,  etc. 

The  second  class,  or  oxygenated  substances,  can 
be  removed  by  shaking  the  "light  oils"  with  a 
solution  of  soda,  with  which  sodium  phenolates,  etc., 
will  form,  while  the  basic  compounds  can  be  removed 
by  treating  the  "oils"  with  dilute  acids. 

The  residue  left  after  the  second  treatment  is  a 
mixture  of  hydrocarbons,  which  are  the  starting- 
point  of  a  new  homologous  series  of  aromatic  com- 
pounds, are  separable  into  its  constituents  by  frac- 
tional distillation,  etc. 

Coal-tar  is  the  chief  source  of  benzene. 

It  is  a  by-product  in  gas  manufacture.  Bitumin- 
ous coal  yields  most  coal-tar,  while  anthracite  coal 
yields  least. 

The  coal  is  subjected  to  destructive  distillation  in 
the  process  of  gas  making  in  fire-clay  retorts,  6  to  8 
feet  long  and  10  wide.  Iron  retorts  were  formerly 
employed  for  this  purpose,  but  this  metal,  being 
readily  attacked  by  sulfur,  has  been  substituted  by 
fire-clay. 

When  coal  is  subjected  to  destructive  distillation, 
the  degree  of  heat  employed  has  a  great  influence 


ILLUMINATING    GAS.  409 

upon  the  percentage  and  character  of  the  fractions; 

thus: 

At 


2  5 


High  temperature 

Gas, 

NHjH.O, 

Tar, 

Sulfur, 

Water, 

s. 

20.5% 

31% 
17-1% 

3-o% 

4.2% 

47-9% 
45 -0% 

0.3% 

6.8% 

loo.o  part 

Low  temperature. 

6.5% 

7.2% 

26.5% 

(above  ioo%  C, 
Fixed  carbon, 
Sulfur, 
Ash, 

40.2% 
50.0% 

9-0% 
5.          99.2  parts. 

A  ton  of  coal  "furnishes  the  following  products  of 
destructive  distillation:  11,000  cubic  feet  of  gas  and 
9  gallons  of  tar. 

ILLUMINATING  GAS  is  composed  of  hydrogen, 
marsh  gas,  carbon  monoxid,  heavy  hydrocarbons, 
hydrosulfuric  acid,  ammonia,  etc.  When  subjected 
to  purification  by  being  passed  first  through  water 
and  then  through  burnt  lime  (CaO)  or  iron  hydrate 
and  lime,  its  composition  changes;  thus: 


Before  purification. 

After  purification. 

H, 

47% 

51% 

CH4, 

34% 

36% 

CO, 

5% 

5% 

Heavy  hydrocarbons. 

4% 

4% 

H,S, 

1% 

none 

NH3, 

1% 

none 

CO,, 

4% 

none 

N, 

4% 

__i% 

In 

100  parts 

In 

100  parts 

To    enrich    the   gas   or    "carburette"    it,    higher 
hydrocarbons    are    employed,    such    as    naphtha. 


4IO  PHARMACEUTIC    CHEMISTRY, 

benzene,  nai)hthalene,  etc.;  nai)hthalene  cannot  be 
used  to  advanta>fe  in  the  winter  time,  as  it  freezes  out. 

FRACTIONS  OBTAINED  BY  DESTRUCTIVELY 
DISTILLING  COAL. 

The  fraction  that  passes  below  80°  C.  is  gas. 

The  fraction  that  passes  between  80  and  170°  C. 
constitutes  "light  oils." 

The  fraction  that  passes  between  210  and  270°  C. 
is  composed  of  creasote  oil,  middle  oil  (phenol), 
naphthalene,  and  constitutes  the  "heavy  oils." 

The  fraction  passing  above  270°  C.  is  chiefly 
anthracene. 

The  "light  oils"  come  over  to  the  extent  of  2  to  4°, 
when  they  are  fractionated;  "dead  oil"  is  left 
behind. 

The  "heavy  oils"  are  found  to  the  extent  of  32 
to  35%,  and  coke  to  the  extent  of  45%. 

The  "heavy  coal-tar  oil"  is  not  further  ])unhed, 
but  since  it  possesses  antiseptic  properties  on  account 
of  the  phenols  it  contains,  it  is  used  as  a  preservative 
for  telegraph  poles,  for  piles  for  bridges,  for  railway- 
sleepers  and  timber  in  general. 

The  light  oils  possess  an  unpleasant  odor,  and 
quickly  acquire  a  brown  color  by  absorbing  oxygen 
from  the  air;  by  shaking  with  HjSO^,  however, 
these  oxidizable  bodies  are  charred  into  a  tarry  mass 
and  can  be  removed. 

The  separation  of  the  constituents  of  the  differ- 
ent fractions  will  be  dcscril^ed  together  with  the 
discussion  of  the  sul)stanccs  themselves. 


411 


BENZENE. 

Benzene  is  sometimes  called  benzol,  phenyl-hydrid, 
coal-tar  benzin;  its  chemical  formula  is  CgHg,  or 
CgH-H  (Faraday,  1825);  it  has  a  boiling-point,  of 
80.5°  C.     Specific  gravity,  0.9  at  0°,  0.87  at  25°. 

Preparation. — From  coal-car  it  is  obtained  by  the 
fractional  distillation  of  the  "light  oils." 

The  fraction  boiling  between  80°  and  150°  C.  is 
employed  for  the  preparation  of  benzene  and  its 
homologues. 

The  homologues  are  removed  by  agitation  with 
strong  H2SO4. 

The  acid  removes  anilin,  pyridin,  etc.;  when  it  is 
withdrawn,  the  "oils"  are  treated  with  strong 
solution  of  caustic  soda  which  unites  with  the 
phenol,  forming  sodium  phenolate  and  neutralizes 
the  residual  sulfuric  acid.  When  the  soda  solution  is 
drawn  off,  the  residual  oil  is  washed  with  water 
and,  so  purified,  subjected  to  fractional  distillation 
in  apparatus  heated  by  steam  and  provided  with  a 
long  fractionating  column. 

The  fraction  which  is  first  collected  is  known  as  a 
"50%  benzene"  or  as  a  "90%  benzene."  These 
terms  signify  a  benzene  in  mixture  of  its  higher 
homologues  as  toluene  and  xylene.  They  indicate 
that  at  100°  C,  50%  of  the  liquid  will  distill  over  in 
the  case  of  the  ftjty  per  cent,  kind;  and  90%  in  the 
case  of  the  ninety  per  cent.  kind.  The  fractions 
having  higher  boiling-points  are  known  as  "solvent 
naphtha,"  used  as  a  solvent  in  the  rubber  industry, 


412  PHARMACEUTIC    CHEMISTRY. 

in  water-proofing  fabrics  and  for  illuminating 
purposes. 

The  "50%"  and  "90%"  benzenes,  by  a  second 
fractional  distillation,  are  separated  into  benzene, 
toluene,  xylene  and  thiophene  (C^H^S). 

Synthetic  Production. — (i)  Benzene  may  be  syn- 

thetized  by  treating  sodium  benzoate  with  caustic 

soda,  just   as    methane    is   prepared    from  sodium 

acetate  and  caustic  soda;  thus: 

C6H5— COONa    +    NaOH    =     C6H6    +    Na.COj 

benzene 
CH3— COONa    +    NaOH    =      CH4      +    Na^COj 

methane 

(2)  By  heating  benzoic  acid  with  lime: 
C^HsCOOH  +  CaO  =  CeH^  +  CaCOg. 

(3)  By  heating  acetylene  to  redness  in  a  tube  of 
hard  glass,  when  it  polymerizes  (Berthelot) : 

3C2H2  =  CgH^. 

Benzene  is,  therefore,  a  polymer  of  acetylene,  and 

on    this    polymerization    the    graphic    structure    of 

benzene  may  be  based;  thus: 

H  H 

I  i 

C  C 

III  /    \ 

H— C      C— H  H— C         C— H 

III  —  II  I 

H— C     C— H  H— C         C— H 

J"  \^ 

Ic  =  I 


3  molecules  of  acetylene  i  molecule  of  benzene 


BENZENE — PROPERTIES  AND   CONSTITUTION.   413 

When  benzene  is  heated  in  a  red-hot  tube,  it  is 
reconverted  into  acetylene  (not  very  completely). 

Properties. — When  cooled  to  o°  C,  benzene 
solidifies  to  a  solid  mass  which  melts  at  6°  C.  It  is 
insoluble  in  HjO,  but  soluble  in  other  solvents;  it 
burns  with  a  sooty  flame,  and  is  a  good  solvent  for 
fats,  resins,  sulfur,  iodin,  etc.  Its  chief  impurity, 
thiophene,  is  separated  from  it  by  adding  concen- 
trated H2SO4,  freezing  it,  and  then  pouring  off  the 
charred  impurities  from  the  crystalline  mass. 

Benzene  combines  with  2,  4  and  6  hydrogen  atoms, 
forming  additive  compounds,  as  benzene  hexahydrid, 
CgHi2  (also  found  in  Russian  petroleum).  With  the 
halogens  it  forms  different  substitution  compounds. 

The  difference  between  these  two  classes  of  de- 
rivatives should  be  clearly  distinguished:  additive 
compounds  are  named  similarly  to  the  inorganic 
compounds;  thus,  benzene  dichlorid,  CgHgClj,  cor- 
responds to  mercury  dichlorid,  HgClj.  Whereas 
substitution  compounds  are  distinguished  by  at- 
taching the  names  and  numerical  proportions  of  the 
substituting  bodies  to  the  parent  substance;  thus, 
CgH^Clj  corresponds  to  dichlorbenzene. 

Additive  Compounds.  Substitution  Compounds. 

Benzene  hexahydrid  =C6H6H6  C6Br6  =  hexabrombenzene. 
Benzene  hexachlorid  =C6H6Cl6  C6Cl6  =  hexachlorbenzene. 
Benzene  tribromid      =C6H6Br3     C6H3l3  =  triiodobenzene. 

CONSTITUTION  OF  BENZENE. 

Kekule  (1866)  was  the  first  to  propose  the  hexava- 
lent  benzene  nucleus.  That  is  to  say,  three  of  the 
four   carbon   bonds   are   used   up    in   linking   with 


414  PHARMACEUTIC    CHEMISTRY. 

adjacent  carbon  atoms,  and  the  fourth  bond  is  united 
with  hydrogen  or  other  elements  or  groups  of  elements. 

Secondly,  he  showed  that  the  six  hydrogen  atoms 
are  eqiii-valent;  that  is,  when  either  one  is  substituted 
by  another  atom,  one,  and  only  one,  derivative  can  be 
obtained.  And  in  reality  there  are  no  isomeric  mono- 
substitution  compounds  of  benzene. 

Thirdly,  that  only  three  disuhstitution  compounds 
can  exist,  and  in  reality  only  three  have  ever  been 
prepared. 

This  has  been  equally  true  when  both  the  substitut- 
ing groups  are  the  same,  as  in  dimethylbenzene,  and 
when  both  the  groups  are  different,  as  in  methyl- 
amido  benzene. 

Fourthly,  that  with  three  similar  substituting 
groups  only  three  isomeric  trisuhstitution  derivatives 
are  possible,  and  in  reality  only  three  trisubstitution 
products  of  benzene  are  known. 

In  opposition  to  Kekule's  theory,  some  chemists 
hold:  First,  that  unsaturated  compounds  of  the  fatty 
series  in  which  the  olefinic  linking  (double-bond)  is 
assumed,  such  as  ethylene,  allyl  alcohol,  etc.,  pos- 
sess the  property  of  forming  with  bromin  addition 
compounds  at  the  ordinary  temperature  without 
splitting  off  hydrogen  and  forming  hydrobromic  acid, 
which  fact  is  in  contradistinction  to  the  parafEnic 
linking  (single  bond)  in  which  the  hydrogen  is  split 
off  with  the  formation  of  substitution  compounds. 
Thus,  if  Kekule's  assumption  were  correct,  six 
bromin  atoms -would  unite  directly  with  benzene 
under  ordinary  conditions,   which,   however,  occurs 


THE    BKNZENE    RING. 


415 


only  in  direct  sunlight,  therefore  not  without  the  aid 
of  active  force.  Secondly,  there  must  be  possible, 
according  to  Kekule's  theory,  two  orthodisubstitu- 
tion  derivatives;  one  of  them  where  the  adjacent  two 
carbon  atoms  are  linked  by  a  double  bond: 
+  '  + 


+ 


II 


Others  suggested  benzene  nuclei  in  which  the  alter- 
nate single  and  double  bonds  are  done  away  with, 
and  nine  single  bonds  introduced  instead,  as  the  one 
shown  in  the  Armstrong  ring: 

I  I 


:i> 

<i 

-     — c— 

— c- 

1 

— c- 

\ 

( 

\ 
( 

/ 
" 

Armstrong's 
nucleus 

Ladenburg  t 

prism 

1 

1 

c 

/1\ 

— C  X,     ^  c— 

1                   1 

1            1^ 

"'<p" 

Bayer's  centri 
formula 

ind  — * 


4l6  PHARMACEUTIC    CHEMISTRY. 

in  which  each  carbon  is  united  with  two  carbons 
and  one  hydrogen,  thus  linking  three  bonds,  while 
the  fourth  bond  is  called  the  centric,  potential  or 
residual,  which  is  portrayed  by  an  arrow  pointing  to 
the  center  and  signifies  a  modified  bond  of  a  some- 
what ill-defined  character. 

Chemists  have  for  these  many  reasons  been  forced 
to  relinquish  the  Kekule  formula  and,  wanting 
further  proof  to  establish  the  others  proposed,  avoid 
any  hypothesis  concerning  the  structure  of  benzene 
nucleus,  adhering  to  the  simple  hexagon  formula: 


each  angle  of  which  is  assumed  to  represent  a  carbon 
and  a  hydrogen  atom,  and  only  the  groups  which 
substitute  the  hydrogen,  are  represented;  thus,  in 
stead  of 

CH3 


c 

-     CH3 

/\ 

H-C       C-NH,„ 

/\-NH, 

II        1 

the  following 

H-C       C-H 

\^ 

\/ 

C 

1 

1 
H 

stands  for  methvl-amido  benzene. 


HEXAMETHYLENEAMIN.  417 

When  each  carbon  of  the  nucleus  is  linked  with 
two  hydrogens,  we  have  the  formula  of 
H        H 

\  / 

C 

H\    /  \  /H 

C         C 
H/l  I  \H=Hexamethylene. 


H  H 

Hexamethylene  is  unimportant,  but  its  amin-deri- 
vative,  which  is  obtained  by  evaporating  a  solution  of 
formic  aldehyd  and  ammonia,  is  important;  thus,  we 
condense: 

6CH3O    +  4NH,OH   =   (CH3)eN,    +   loH^O 

forma)  dehyd  hexamethylene 

tetramin 

HEXAMETHYLENEAMIN  (hexamethylamina  U.  S. 
P.),  is  a  crystalline  substance  sold  under  various 
names,  as  cystogen,  formin,  aminoform,  urotropin, 
etc.  Soluble  in  water.  Employed  as  antiseptic  in 
purulent  affections  of  kidneys  and  bladder. 


CO 

w 

W 

CO 
N 

m 
W 

H 
O  I 

CO    S 

§^ 

<3 
O 

o 
p 

w 

Q 
M 
H 
< 

H 
< 

CO 


o    o    o    o 

o    o    o    o    o    o 

O      0 

c " 

<N  o  t^  -1- 

O    CN  "->  O    ON 

00    r^ 

a 

6  " 

Tj-   ro  ro  i-O 

^O  \0    r^vo    LO^O 

u->  m 

rS)    " 

H      M      M      1-1 

M      M 

i 

d-dd, 

add                 1 

^_Qxi 

•9-9-° 

'o 

6  £   d 

iga 

SI 

~ 

f^o 

00  00 

2 

o  d 

tc 

o~"^^o^ 

oT" 

^^ 

££ 

^i^^ 

o 

^ 

"S 

O  M 

vO   in  '^  '^ 

00_ 

ro 

^§8 

^§S§§ 

£■ 

^ 

d  d 

d  d  o  0 

d 

d 

1       g' 

a 
u 

^ 

o             ^ 

ffi  ^ 

S 

rt 

Z 

U 

If 

^  A  § 
ilisi  1 

-"    OJ    o    g    >,    -^ 

l! 

^ 

o 

^X 

ffi 

E 

66 

U 

U 

^ 

OOOOO                              O                          OO 

' 

O  O   lo 

•^     -1-                                  lO                             M      « 

**    Tl- 

'I 

t^Os  o 

O                     r-                u^ro 

^o  ^    . 

M                             M                                  N 

M     PI 

be 

-    _    _ 

-     -                      -                   _     „ 

~      - 

.S 

cidd 

d.d.             d.           dd 

dd 

'o 

pxfxi 

£  -              -             £  xi 

B~ 

m 

>. 

> 

iS 

M 

g~^ 

(_, 

o 

<J3 

■^ 

so 

CI. 

lo 

CO 

00 

o' 

^ 

lO 

w 

J 

5 

K       " 

■^ 

o     3              ^''t: 

X 

u 

4,^ 

Jo 

c 

5 

V-  =Prehnitene, 

Dimethylethyl  benze: 

Six  isomers  possible. 

Diethyl  benzenes  (^) 

1  Cymene,  C6H4(CH3)( 

Six  isomers  possible. 

Butyl  benzenes,  C6H5 

Four  isomers  possible, 

1  Pentamethyl  benzene, 

[  Amyl  benzene,  etc.,  C 

0 

il 

£  j= 

H_ 

J,     rt 

ffiH 

' 

? 

00 

«                 w 

ffi 

M                                                                                   f^ 

^                    u 

c5 

CHAPTER  XXXIII. 
BENZENE  DERIVATIVES. 

Of  the  twenty-seven  aromatic  hydrocarbons  given 
in  the  table,  only  the  first  four  are  found  in  coal-tar: 
Benzene,  CeHe,  or  benzol.  Synonyms.  Structure. 

Toluene,  C7H8,  or  toluol     =  methylbenzene,      C6H5CH3 
Xylene,    CgHio,  or  xylol      =  dimethylbenzene,  C6H4(CH3)2 
Cumene,  C9H12,  or  cumol    =  trimethylbenzene,  C6H3(CH3)3 

The  higher  homologues  can  all  be  formed  by 
synthesis.  While  but  one  benzene  and  one  toluene 
are  known,  the  higher  hydrocarbons  form  several 
isomers. 

Properties. — The  closed-chain  hydrocarbons  are 
acted  on  more  easily  by  strong  sulfuric  and  nitric 
acids  than  the  paraffins.  The  aromatic  derivatives 
are  more  resistant  to  oxidizing  agents. 

When  nitrous  acid  is  allowed  to  act  on  the  aromatic 
amins,  diazo  compounds  are  formed:  Diazo  com- 
pounds exhibit  two  nitrogen  atoms  linked  together; 
to  these  is  linked  a  radical  by  two  bonds,  and  one 
bond  remains  free. 

The  aromatic  hydrocarbons,  similarly  with  the 
aliphatic,  form  alcohols,  aldchyds,  ethers,  ketones, 
halid  derivatives,  amins,  nitro  compounds,  acids,  etc. 

When  benzene  is  treated  by  bromin,  it  forms  a  sub- 
stitution product — monobrombenzene,  CgHgBr;  mono- 
brombenzene,  in   turn,  when  acted   upon  by  nitric 
acid,  forms  nitrobrombenzene,  CgH^.NOj.Br. 
418 


MONOSUBSTITUTED    BENZENE.  419 

Thus,  C^Hg  had  one  of  its  six  hydrogens  replaced 
by  Br,  and  another  one  by  the— NOj  group.  If  we 
now  treat  nitrobrombenzene  with  nascent  hydrogen, 
we  can  remove  the  bromin  and  obtain  nitrobenzene, 
CgH^.NOj.H,  in  which  the  nitro  group  is  easily 
replaced  by  bromin,  again  forming  monobrom- 
benzene,  CeH.BrH. 

Without  going  into  much  detail,  the  above  plainly 
explains  how  it  is  possible  to  know  that  in  replacing 
successive  hydrogens  in  benzene  a  different  hydrogen 
atom  is  replaced  in  each  reaction. 

Thus,  in  the  monobrombenzene  produced,  by  re- 
placing the  — NO2  group  with  bromin,  we  have  cer- 
tainly replaced  a  different  hydrogen  atom  from  that 
replaced  in  the  first  reaction.  The  two  monobrom- 
benzenes,  however,  are  identical — proving  that  only 
one  yno  no  substitution  benzene  can  exist,  and  in  reality 
the  mono-substituted  benzenes  have  no  isomers. 

The  above  examples  of  the  substitution  of  benzene 
can  be  further  made  plain  by  assuming  that  each 
angle  of  the  benzene  nucleus  contains  one  carbon 
atom  in  combination  with  one  hydrogen  atom;  and 
that  each  carbon  and  hydrogen  can  be  numbered 
consecutively,  starting  at  the  top  of  the  ring: 


6A2 


.     If,  in  addition,  we  represent  benzen:;  by 

5\/3 

4 

12      34      S     6 

C„H,H,H,H,H,H,   we  can  begin   to  argue  out  the 


420  PHARMACEUTIC    CHEMISTRY. 

substitution.     Let  us  assume  that  bromin  substituted 
the  hydrogen  numbered  one.   we  will  then  have  a 
Br 

II  23456 

monobrombenzene,  ,    written    C^BrHHHHH. 

5\/3 
4 
This  product  treated  with  nitric  acid  will  yield  us 
nitrobrombenzene  by  substituting  the  next  adjacent 
Br 
6/'\N02 

hydrogen  numbered  two,  ,    writtten    C^Br- 

5\/3 
4 
3456 
NO2HHHH. 

By  treating  the  above  compound  with  hydrogen, 
the  bromin  is  removed  and  nitrobenzene  produced, 

I 
6/\NO, 

I        I        ,  written      CgHNO.HHHH.       From     the 
5\/3 

4 
above    it    is    plain    that    the    hydrogen    numbered 
one   has    been    reestablished.      If  we   now  attempt 
further    reduction   of  nitrobenzene   with    hydrogen, 
I 
6/\NH2 

amido  benzene  is  produced,  ,  written  C^- 

5\/3 


ISOMERISM.  421 

I  3456 

HNHjHHHH,  which  by  treatment  with  bromin  is 

6/\Br 

again  converted  into  monobrombenzene,  , 

5\/3 
4 
I        3456 
written  CeHBrHHHH,  and  showing  that  a  different 
hydrogen  has  been  replaced  in  this  last  reaction  than 
in  the  first.     Therefore,   it  is  safe  to  assume  that 
if  the  replaceable  hydrogen  atoms  are  equivalent, 
the  six  carbon  atoms  must  be  united  into  a  closed 
chain  which  is  stable  and  hard  to  break  up. 

ISOMERISMS. 

(i)  Assuming  Kekule  's  hypothesis  of  the  closed  ben- 
zene ring,  we  can  have  one  only  monosiibstituted  benzene 
irrespective  of  which  hydrogen  atom  was  replaced. 

(2)  We  find  three  disubstitution  products: 
Replacing    the    hydrogens  i,   2    or  i,   6,    named 

or//^o-position ;  replacing  the  hydrogens  i,  3  or  i,  5, 
named  me/a-position;  replacing  the  hydrogens  i,  4, 
named  para-position,  in  which  the  replacing  groups 
are  adjacent  or  vicinal,  as  in  the  ortJio  (abbreviated-o), 
alternate  as  the  meta  (abbreviated-m),  or  opposite  as 
in  the  para  (abbreviated-p)  position. 

(3)  Where  the  substituting  groups  are  all  alike,  we 
have  three  trisubstitution  products: 

Replacing  hydrogens  i,  2,  3,  named  consecutive 
or  adjacent;  replacing  hydrogens  i,  3,  5,  named 
symmetric;  replacing  hydrogens  i,  2,  4,  named 
asymmetric  or  irregular. 


422 


PHARMACEUTIC    CHEMISTRY. 


(4)  There  can  be  six  trisiihstitution  compounds, 
of  two  substituting  groups. 

(5)  There  can  be  ten  trisiihstitution  compounds,  of 
three  substituting  groups. 

(6)  There  can  be  three  tetrasubstitution  products 
where  the  substituting  groups  are  alike: 

Replacing  hydrogens  i,  2,  3,  4,  named  consecutive; 
replacing  hydrogens  i,  2,  4,  5,  named  symmetric; 
replacing  hydrogens  i,  2,  3,  5,  named  asymmetric  or 
irregular. 

(7)  There  are  seven  tetrasubstitution  compounds, 
of  two  substituting  groups. 

(8)  Sixteen  tetra  compounds,  with  three  substituting 
groups. 

(9)  Thirty  tetra  compounds  with  jour  substituting 
groups. 

(10)  There  is  but  one  penta-substitution  product, 
just  as  there  is  but  one  hexa  substitute. 

IDENTIFICATION  OF  DISUBSTITUTED 
BENZENES. 
Taking    dibrombenzenes    as    example,    we    have 
three,    all    having    the    same    molecular    formula. 


Br 

/\Br 


Br 


Br 


Br 


Br 


(1)  orthodibrom-be-i-  (i)   metadibrom- 

zene    melting-  benzene  a  liquid 

point  1°;  boiling-  — boiling-point 

point  2  2  4°  *i9° 


(3)  paradibrom- 
benzene  melting- 
point  89°;  boil- 
ing-point 219° 


BROM-BENZENES. 


423 


It  will  be  seen  that  while  (i)  is  different  from  (2) 
and  (3)  in  its  boiling-point,  the  latter  two  are 
identical,  both  boiling  at  219°  C;  but  (3)  solidifies 
at  89°  C.  and  is  ordinarily  a  solid,  while  (2)  is  always 
a  liquid. 

By  converting  the  dibrombenzenes  into  tribrom- 
benzenes,  we  can  obtain  from  the  ortho  but  two 
trisuhstitution  benzenes:  thus: 


Br 


Br 


o.  di-brombenzene 


Br 


(1) 


Br 


Br 


Br 


Br 

(2) 


Br 


From  the  nieta  three  trisuhstitution  benzenes  can 
be  obtained;  thus: 


Br 


Br  Br 

Br 


m.  di-brom- 
benzene (i) 


Br 


Br 

(2) 


Br 


Br    Br   .      ,  Br 


(3) 


424  PHARMACEUTIC    CHEMISTRY. 

From  the  para  but    one  trisubstitution  benzene 
can  be  obtained;  thus: 

Br  Br 


Br 

Br  Br 

p.  di-brombenzene 

Therefore,  ortho  compounds  are  those  furnishing 
two  trisubstitutes;  meta  compounds  are  those  fur- 
nishing three  trisubstitutes;  para  compounds  are 
those  furnishing  one  trisubstitute. 

SYNTHESIS  OF  THE  BENZENE  HOMOLOGUES. 

The  homologues  of  benzene  are  synthesized  in  a 
way  similar  to  the  preparation  of  the  methane  homo- 
logues by  either  of  two  following  reactions: 

(i)  Fittig's  reaction  is  brought  about  when  halid 
derivatives  of  benzene  or  one  of  its  homologues  and 
an  alkyl  halid  in  ethereal  solution  are  treated  with 
metallic  sodium  or  potassium: 

C,H,Br     +  rH,Br  +  Na,  =   CeH^.CH,   +  2NaBr 

Drombenzene  niethylbenzene 

(toluene) 

QH^BrCH,  +  CH^Br  +  Na,  = 

bromtoluene 

^«"^\Ch'     +     2NaBr,  etc. 

limethyl  benzene 
(xylene) 


HALOGEN   DERIVATIVES    OF    BENZENE.  425 

(2)  Friedel  and  Craft's  reaction  consists  in  adding 
anhydrous  aluminum  chlorid  to  a  mixture  of  an 
aromatic  hydrocarbon  and  an  alkyl  chlorid;  corre- 
sponding homologues  are  formed  and  hydrochloric 
acid  evolved;  thus: 

CfiHe    +    CH3CI    =    C6H3.CH3       +    HCl. 
CfiHe    +    2CH3CI    =    C6H,(CH3),    +    2HCI. 
CgH5.C3H5  +  CH3Cl  =  C6H,(CH3).C2H5  +  4HCI,  etc. 

Properties. — The  benzene  homologues  are  volatile, 
oily  liquids,  insoluble  in  water,  soluble  in  alcohol  and 
ether.  They  form  two  classes  of  derivatives:  {a) 
when  the  substituting  group  replaces  hydrogen  in  the 
benzene  nucleus  and  (&)  when  it  replaces  hydrogen 
in  the  alkyl  group,  "side  chain." 

HALOGEN  DERIVATIVES  OF  BENZENE. 

When  a  current  of  chlorin  is  passed  into  benzene 
at  ordinary  temperature,  monochlorhenzene,  CgH5Cl, 
is  formed.     It  can  also  be  produced  from  phenol  by 
acting  with  phosphorus  chlorid  upon  it;  thus: 
3QH,0H    +   PCI3   =    sCqH.CI    +    H3PO3 

phenol  monochlor 

benzene. 

Description. — It  is  a  colorless  liquid,  boiling  at  136°. 
Through  the  continued  action  of  chlorin  at  ordinary 
temperature  upon  this,  especially  in  presence  of  a 
trace  of  iodin,  hexachlorbenzene,  CgCle,  is  produced. 
When  chlorin  acts  upon  benzene  at  the  temperature 
of  the  boiling-point,  benzene  hexachlorid  is  formed; 
this  substance  has  the  formula  CgHgClg.  Benzene 
hexachlorid  is  a  colorless,  crystalline  body,  melting 


426  PHARMACEUTIC    CHEMISTRY. 

at   157°  C,  and  when  heated  decomposes  into  tri- 
chlorbenzene,  CgHgClg,  splitting  off  hydrochloric  acid: 
CsH.Cle  =  CeH3Cl3  +  3HCI. 
Benzene  hexahromid  is  similarly  prepared  by  action 
of  bromin. 

NITRO-DERIVATIVES  OF  BENZENE. 

When  benzene  is  slowly  acted  upon  by  nitric  acid 
gradually  added,  niirobenzene,  CgHgNOj,  is  formed. 
This  product  is  washed  with  water,  dried  over 
calcium  chlorid,  and  redistilled.  It  is  a  yellowish, 
oily  liquid,  boiling  at  205  °  C,  and  possessing  a  strong 
odor  of  the  oil  of  bitter  almonds.  It  is  poisonous, 
and  known  under  the  synonyms  of  oil  of  mirrbane  and 
''artificial  oil  of  bitter  almonds."  This  latter  term 
is  especially  dangerous  in  that  it  may  be  confounded 
with  benzaldehyd.     Reaction: 

CeH«  +  HNO3  =  CeH,.N03  +  H,0. 

Dinitrobenzenes. — When  benzene  is  boiled  with 
fuming  nitric  acid,  two  hydrogen  atoms  are  substi- 
tuted and  dinitrobenzene,  C8H^(N02)2,  is  formed. 
The  dinitrobenzenes  exist  in  three  modifications, 
which  may  be  distinguished  by  their  melting-points, 
crystalline  forms,  etc. 

Me/a -DINITROBENZENE  is  best  obtained  by 
heating  nitrobenzene  for  half  an  hour  with  a  mixture 
of  nitric  and  sulfuric  acids.  The  product  is  poured 
into  cold  water,  the  precipitate  washed,  dried  and 
crystallized  from  alcohol.  Pale  yellow  crystals,  melt- 
ing at  90°,  and  soluble  in  organic  solvents. 


SULFO-DERIVATIVES    OF    BENZENE.  427 

Or//zo-DINITROBENZENE  is  the  principal  pro- 
duct when  benzene  is  boiled  with  strong  fuming 
nitric  acid.     Scales  melting  at  ii8°  C. 

Para-dinilrobenzene  is  a  by-product  in  both  the 
above  reactions.     Crystals  melting  at  1 73  °  C. 

Trinitrobenzenes  can  be  obtained  by  heating 
any  of  the  dinitrobenzenes  with  a  mixture  of  nitric 
and  sulfuric  acids,  they  each  furnishing  a  different 
trinitrobenzene. 

NO2  NO,  NO2  NO2 

/\  /\  /\  /\ 

NO., 


/  NO2 

\/ ■■-/ '-/ . 

nitrobenzene       o — di-nitrobenzene         no.  di-nitro-  NOj 

benzene  -r-. — t- — 


SULFO-DERIVATIVES  OF  BENZENE. 

When  we  boil  benzene  with  strong  sulfuric  acid, 
it  slowly  dissolves,  forming  benzene-sidjonic  acid, 
CgHsSOjOH,  through  the  substitution  of  the  sul- 
fonic group  (SO.OH)  for  one  hydrogen  atom. 

Benzene-suljonic  acid  occurs  in  colorless  plates, 
deliquescent,  soluble  in  water  and  alcohol.  With 
metals  this  acid  forms  a  series  of  soluble  salts, 
called  benzene  sulfonates.  When  benzene  is  boiled 
with  large  quantities  of  sulfuric  acid,  benzene-disul- 
fonic  acids  are  produced. 


428  PHARMACEUTIC    CHEMISTRY. 

Preparation. — By  treating  the  hydrocarbons  with 
sulfuric  acid: 

/SO3 
C^H,  +  H3SO,  =  CeH,/  +  H,0 

Ml 

benzene  sulfonic 
acid 


Structure.— C^U.^—S^OYi. 

When  sulfonic  acids  are  fused  with  potassium 
hydroxid,  the  hydroxyl  replaces  the  sulfonic  group 
and  phenol  is  formed: 

SO3 
C3H/  +  KOH  =  CeHjOH  +  K^SOj 

When  anilin,  C6H5.NH2,  is  treated  with  sulfuric 

NH, 
acid,    suljanilic     acid    is     formed,   CuH^(^  , 

\sO3H. 

called  /»(7;-<z-sulfonic  acid: 

/NH, 
C^H^.NH^  +  H^SO,  =  C«H,(         "     +  H,0. 
\SO3H 

Sulfanilic  acid  is  sparingly  soluble  in  cold  water; 
more  soluble  in  hot  water.  It  crystallizes  in  plates. 
When  treated  with  nitrous  acid,  it  yields  diazobenzene 

/  N,.OH 
sulfonic  acid,  ChH4('  ;    this    heated  with    di- 

^S03H 

methyl-anilin    gives    HELIANTHIN,  tropacoUn    D, 


TOLUENE   AND    ITS    DERIVATIVES.  429 

methyl-orange,  "Poirrier's  orange,"  a  valuable  indi- 
cator in  analytic  chemistry: 

/SO3H 

CgH,— N2— CeH^.NCCHg),. 

dimethyl  anilin  azobenzene  sulfonic 
acid.     (Helianthin.) 

TOLUENE  AND  ITS  DERIVATIVES. 

Toluene,  CgH^.  CH3,  also  called  toluol,  was  so 
named  from  '*  tolu-balsam,"  from  which  it  was  first 
obtained  by  distillation  (Pelletier,  1832).  Toluene, 
phenyl-methane,  is  a  light,  mobile,  oily  liquid,  insolu- 
ble in  water,  boiling  at  1 10°,  but  otherwise  resembling 
benzene.  It  occurs  in  coal-tar  and  balsam  of  tolu 
oil;  it  can  be  prepared  by  FUtig's  reaction.  When 
subjected  to  oxidation,  only  the  methyl  (side-chain) 
group  becomes  oxidized,  giving  rise  to  benzoic  acid: 

CeHs.CHa  +  03  =  CsHs.COOH  +  H2O. 

toluene  benzoic  acid 

The  synthesis  of  toluene  from  benzene  clearly  indi- 
CH, 


cates  its  structure  to  be 


Toluene  is  some- 


times considered  as  a  methane,  in  which  one  hvdro- 

CH3 

gen  was  replaced  by  the  phenyl  group;  thus,   |      = 

CeHg. 

phenyl-methane. 


43° 


PHARMACEUTIC    CHEMISTRY. 


The  term  phenyl  is  applied  to  the  monovalent 
radical  CgHj'  of  benzene,  and  the  "aryl"  replaces 
iilkyl  among  the  aromatic  radicals. 

DERIVATIVES  OF  TOLUENE. 


CHLORIN  DERIVATIVES.— Like  benzene,  toluene 
forms  substitution-products  with  chlorin  and  bromin. 
The  substitution  may  take  place  either  in  the  side 
chain  or  in  the  nucleus.  By  boiling  toluene  and 
passing  chlorin  into  it,  substitution  in  the  side  chain 
will  occur;  the  following  products  being  successively 
produced : 


CeH,.CH3.Cl   - 

benzyl  chlorid 


CgH^CHrCl^   —    CgHg.CCla' 

benzal  chlorid  benzenyl  chlorid 

(Benzyledene 
chlorid) 


The  first  compound  contains  the  monovalent  rad- 
ical benzyl,  CgHj.CH/;  the  second,  a  divalent  radical 
benzal,  CgH^.CH''',  and  the  third,  a  trivalent  radical 
benzenyl,  C6H5.C  ". 

If  chlorin  is  passed  into  cold  toluene,  sul)stitution 
takes  place  in  the  nucleus,  and  mono-,  di-  and 
trichlor-  toluenes  are  produced. 

Examples  of  substitution  in  the  side  chain: 

CH2.CI  CH-.Cl^  C  :  CI3 


XYLENES   AND    THEIR    DERIVATIVES. 


431 


Examples  of  substitution  in  the  nucleus: 

CH3  CH3  CH3 


-CI 


/\ 


—CI 


ortho-chlor 
toluene 


meta-chlor 
toluene 


CI 


para-chlor 

toluene. 


XYLENES    AND    THEIR    DERIVATIVES. 
XYLENE  exists  in  three  modifications: 
Or//j(? -XYLENE    may    be    prepared   by    heating 
methyl  iodid  with  ortho-  bromtoluene  in  presence  of 
metallic  sodium.     It  is  a  colorless  liquid,  boiling  at 
142°,  and  having  a  specific  gravity  of  0.876  (20°). 
CH3 
/\CH3 


Meta-XYLEJUE  is  prepared  by  heating  meta-  iodo- 
toluene  with  methyl  iodid  in  presence  of   metallic 
sodium.     Meta -xylene  boils  at  139°;  specific  gravity, 
CH3 


0.865    (20°). 


CH, 


Pafa-XYLENE  can  be  made  by  methods  similar 
28 


432 


PHARMACEUTIC    CHEMISTRY. 


with  the  above  or  by  distilling  camphor  with  zinc 
chlorid. 

Para -xylene  boils  at  137°  and  has  a  specific  gravity 
of  0.863  (20°). 

CH3 


CH3 

Properties. — When  oxidized,  the  xylenes  yield  the 
dibasic  ortho-,  meta-  and  paraphthalic  acids,  and  by 
substitution  yield  derivatives  similar  to  toluene. 

The  oxidation  occurs  in  two  stages;  thus,  first,  the 
three  tohiic  acids  are  produced: 
CH3  CH3  CH3 

/\COOH  / 


COOH 


COOH 


o-toluic  acid  m-toluic  acid  p-toiuic  acid. 

on  further  oxidation,  each  of  these  yields  a  corre- 
sponding dibasic  acid: 

COOH       COOH       COOH 
/XCOOH   /\        /\ 


COOH 


phthalic  acid 
melting-point 


isophthalic  acid 

melting-point 

300°. 


COOH 

terephthalic  acid 
sublimes  with- 
out melting 


MESITYLENE   AND    CYMENE. 


433 


Mesitylene,  CgH3(CH3)3  (i,  3,  5),  is  produced  by 
the  action  of  strong  sulfuric  acid  upon  acetone: 

3C3H,0  +  [H3SOJ  =  C«H3(CH3)3  +  3H3O. 

Chemically,  trimethyl  benzene  can  be  produced 
from  the  xylenes  by  Fittig's  reaction.  It  boils  at 
160°  C  and  has  a  pleasant  odor.  When  oxidized, 
mesitvlene  yields  a  series  of  acids: 


CH, 


CH, 


CH3  X/CHg 

mesitylene 

CH, 


COOHX/CHg 

mesitylenic  acid 

COOH 


COOH\/COOH  COOH\/COOH 


Cymene,  CgH4.CH3.C3H7,  para-  methyl  pro  pyl-hen- 
zene  occurs  naturally  in  the  essential  oils,  like  oil 
of  thyme,  etc.,  and  can  be  produced  artificially  by 
the  action  of  dehydrating  agents  upon  these. 

Thus,  when  camphor  is  distilled  with  phosphorus 
pentoxid,  cymene  is  produced: 

CipH^gO  =  CjqH^,   +  H2O. 

camphor  cymene 


434  PHARMACEUTIC    CHEMISTRY. 

Cymene  possesses  a  pleasant  odor,  boils  at  175' 
and  has  the  specific  gravity,  0.856  (20°) 
CH3 


Structure. —   X\ 


C3H,. 


C,nH, 


cymene 

DERIVATIVES  OF  THE  HOMOLOGUES. 

CHLORTOLUENE,  toluyl  chlorid,  CeH.Cl.CHj 
occurs  in  three  modifications  like  all  the  disubstituted 
benzenes.  When  cold  toluene  is  acted  upon  with 
chlorin,  a  mixture  of  the  ortho-  and  para-  varieties  is 
produced.  By  treating  the  corresponding  cresols, 
any  of  the  three,  modifications  may  be  produced. 
The  cresols  are  hydroxytolucncs.  Chlortoluenes  boil 
at  about  156°  C. 

BENZYL  CHLORID,  CoH^.CHjCl,  is  prepared  by 
passing  chlorin  into  boiling  toluene,  also  by  acting 
with  phosphorus  chlorid  upon  benzyl  alcohol: 
3C,H,.CH,OH   +  PCI3  =  aCeHs-CH^Cl  +  H3PO3 

benzyl  alcohol  benzyl  chlofid. 

[Benzyl  alcohol  is  ])roduced  by  replacing  one 
hydrogen  atom  of  the  side  chain  in  toluene  with  a 
hydroxyl.] 

Benzylchlorid  is  insoluble  in  water,  but  soluble  in 
organic  solvents,  it  possesses  a  penetrating  odor  and 
boils  at  176°  C.  With  water  it  hydrolyzes  into 
benzyl  alcohol  and  hydrochloric  acid;  with  nitric  acid 
it  forms  nitro  derivatives. 


AROMATIC  AMINS. 


435 


BENZALCHLORID,  CeHj.CHClj,  is  obtained  by 
the  prolonged  boiling  of  toluene  and  chlorin.  It  is 
a  colorless,  oily  liquid,  boiling  at  206°. 

NITROTOLUENES.— When  toluene  is  treated 
with  strong  nitric  acid,  substitution  always  occurs  in 
the  phenyl.  The  chief  nitrotoluene  is  the  para  with 
which  a  little  ortho  compound  forms  at  the  same  time. 
These  may  be  separated  by  fractional  distillation 
since  they  have  different  boiling-points,  besides, 
ortho  is  a  liquid,  the  para  a  crystalline  solid: 
CH3  CH3 


nitrotoluene,  boiling- 
point,  224°. 


NO2 


itrotoluene  boiling- 
point,  237°. 


AROMATIC  AMINS. 

When  a  nitro  compound  is  treated  with  nascent 
hydrogen,  an  aromatic  amin  and  water  are  produced. 
Thus,  if  nitrobenzene,  CgHgNOj,  is  treated  with  a 
mixture  of  metallic  tin  and  hydrochloric  acid, 
hydrogen  is  generated  and  the  nitro  group  reduced  ; 

(i)  sSn  +  6HC1  =  3SnCl2  +  3H,. 

(2)  CeH^NO^  -f  3H2  =  CeHs.NH,  +  2H2O. 

nitrobenzene  anilin 

(phenylamin) 

ANILIN,  amidobenzene,  phenylamin,  CgHgNH^,, 
is   prepared   as   above.      It   was   first  obtained   by 


436 


PHARMACEUTIC    CHEMISTRY. 


distilling  indigo  (Portuguese  for  indigo  is  anil). 
Anilin  is  found  in  coal-tar,  also  in  Dippel's  oil" 
(bone  oil).  It  is  the  simplest  member  of  the  group 
of  aromatic  amins  and  occurs  as  a  colorless  oil 
when  pure — more  frequently  of  a  yellowish  or  brown- 
ish color,  possessing  a  characteristic  odor,  sparingly 
soluble  in  water,  but  readily  in  other  organic  solvents. 
It  boils  at  183°,  is  poisonous,  and  with  the  acids  it 
forms  additive  compounds.  Chemically,  it  is  a 
substituted  ammonia. 

Salts  with  the  acids: 

CeHj.NH,  +  HCl  =C6H5NH2.HCl=anilin  hydro- 
chlorid. 

CeHg.NH^  +  HNO3.  =  C6H5NH2.HNO3  =  anilin 
nitrate. 

aCeH^.NR,  +  H3SO,  =  (CeH,.NH2)2.H2SO,  = 
anilin  sulfate. 

A  nilin  salt  of  the  trade  is  the  anilin  chlorid.  These 
salts  treated  with  alkali  hydroxids  are  resolved  back 
into  anilin,  water  and  a  corresponding  salt;  thus: 
CeHs.NH^.HCl  +  KOH  =  QH.NH^  +  H^O  -f  KCl. 


anilin  chlorid 


NH, 


"N(CH3)3 

I 


Structure. 


\/ 


anilin  boiling-point, 
183°. 


dimethyl  anilin 
melts  at  0.5°;  boiling- 
point,  193". 


ACETANILID — DIPHENYLAMIN.  437 

NH.COCH3  NH.QHs 


\/ 


acetanilid  melting-point, 

115°;  boiling-point,  304°. 


diphenyl  amin  melting- 
point,  54°;  boiling- 
point,  302°. 


CHAPTER  XXXIV. 
DERIVATIVES  OF  ANILIN. 

Anilin  is  much  more  reactive  with  ordinary 
reagents  than  either  benzene  or  its  halid  or  nitro- 
derivatives. 

ALKYL  ANILINS  are  compounds  corresponding 
in  constitution  to  the  secondary  aliphatic  amins.  It 
should  be  remembered  that  we  can  have  primary, 
secondary  and  tertiary  aromatic  amins,  just  as  we  have 
the  aliphatic  substituted  ammonias: 

/CeH,  /CeH,  /CeH, 

^H  \H ^CeHs 

primary  anilin  secondary  anilin  tertiary  anilin 

(phenyl  amin)  (diphenyl  amin  (triphenl  amin). 

Or  we  have  an  alkyl  as  one  of  the  substituting  groups: 
/C„H,  /QII^  /C«H, 

^H  \H  ^CHj 


primary  anilin  methyl  anilin  dimethyl  anilin. 

Identification  oj  Aromatic  Amino  Compounds. — 
They  may  be  identified  much  like  the  aliphatic 
amins. 

(i)  Primary  amins  with  nitrous  acid,  upon  warm- 
ing,  effervesce,    the  NH^  group  is  replaced  by  an 
OH  group: 
C«H5.NH,  +  HNO;  =  CeHjOH  +  Nj  +  H^O. 

anilin  phenol  (hydroxy- 

benzene) 


SECONDARY  AND    TERTIARY  AMINS.  439 

(2)  Secondary  amins  with  nitrous  acid  give 
nitrosamin,  a  yellow  substance,  insoluble  in  water. 
Thus,    methyl    anilin    gives    a    nitrosomethylanilin, 

/NO 
CeH,.N<         : 
\CH3 
C6Hs.NH.CH3  +  HNO.  =  C6HsN.(NO.).CH3  +  H,0. 
methyl  anilin  nitrosomethyl  anilin. 

These  nitrosomethylanilins  can  further  be  reduced 
to  substituted  hydrazins,  CjHj.Nx 

(3)  Tertiary  amins  with  nitrous  acid  give  a  deep 
red  solution,  from  which  yellow  crystals  will  separate; 
thus,  in  the  case  of  dimethylanilin,  nitrosodimethyl- 
anilin  is  formed. 

With  acetyl  chlorid  or  acetic  anhydrid,  primary  and 
secondary  aromatic  amins  form  acetyl  derivatives; 
the  tertiary  amins  do  not;  thus: 

(i)  C6H^H,+CH,CO.Cl^C6H5.NH.CO.CH3+HCl 
primary  acetanilid. 

amin 
(2)  C6H6.NH.CH3  +  CH3CO.CI  =  C6H6.N(CH3).CO.CH3  +  HCl. 
secondary  amin  methyl  acetanilid. 

The  primary  amins,  furthermore,  with  alcoholic 
potash  and  chloroform  give  the  carhamin  (isonitril) 
reaction: 
CeHs.NH.  +  CHCI3  +  3KOH  =  C6H5.NC  +  3KCI  +  3H.0 

anilin  phenylisonitril 

(phenyl  carbamin) 

METHYL  ANILIN,  CgHs.NH.CHa,  is  prepared  by 
acting  with  methyl  chlorid  on  anilin: 

CeH^.NH^  +  CH3CI  =  CfiHs-NH-CHg  +  HCl. 

methyl  anilin 


440  PHARMACEUTIC    CHEMISTRY. 

It    occurs    as    a    strongly   basic    liquid,    boiling    at 
90°  C. 

DIMETHYL  ANILIN,  CeH^.NCCHg),,  is  also  pro- 
duced in  the  previous  reaction.  It  occurs  as  a 
strongly  basic,  oily  liquid,  boiling  2it.jj)o°  C. 

TOLUIDINS     exist     in     three     modifications,    of 

NH2 
which    the     para-toliiidin,    C^^/  ,    prepared 

CH3 
from  para-nitrotoluene,  is  the  best  known.  Tolit- 
idins  are  amido-toluenes  and  bear  the  same  relation 
to  toluene  as  anilin  does  to  benzene.  The  toluidins 
resemble  anilins  in  properties.  When  oxidized, 
toluidin  yields  rosanilin,  the  parent  substance  of 
many  anilin  dyes. 

DIPHENYLAMIN,  (C6H5)2.NH,  is  formed  from 
anilin  by  the  introduction  of  a  second  phenyl,  CgHj,, 
group  in  the  side  chain.  This  is  usually  accom- 
plished   by    heating    anilin   with    anilin    chlorid    at 

200°  C: 

CeH,  NH,  +  C6H^.NH..HC1  =C6H,.NH^C6H5-H  NH4CI. 
anilin  anilin  hydrochlorid        diphenylamin 

Diphenylamin  crystallizes  in  white  lamlpa  from 
ligroin,  and  has  a  melting-point  of  54°,  boiling-point 
of  302°  C.  It  forms  salts  with  strong  acids,  which 
are  decomposed  by  water. 

BENZYLAMIN,  CeHj.CHjNHj;  is  isomeric   with 
toluidin,  and  can  be  prepared,  like  the  alkylamins, 
by  reducing  corresponding  cvano-compounds: 
C„H,.CN    +    2H2    =    CeH5.CH,.NH, 

phenyl  cyanid  benzylamin. 

Benzylamin  resembles  closely  the  alkylamins  in 


DIAMINS.  441 

their  properties.  It  occurs  as  a  mobile,  colorless 
liquid,  soluble  in  water,  with  a  pungent  odor  and  a 
boiling-point  of  185°  C.  Specific  gravity,  0.983 
(19°  C). 

ACETANILID,  acetanilidum  CeH^NH  (CHCO), 
antifebrin,  phenylacetamid.  A  monacetyl  derivative 
of  anilin.  Made  by  the  condensation  of  anilin  and 
glacial  acetic  acid.  A  crystalline  white  powder,  soluble 
in  180  parts  water,  in  25  parts  alcohol,  18  parts  ether 
and  5  parts  chloroform.  Melting-point  113°  C. 
Used  as  antipyretic,  analgesic,  antirheumatic,  seda- 
tive, antiseptic.  Used  in  fevers,  headache,  neuralgia. 
Externally,  as  antiseptic,  instead  of  iodoform.  Also  as 
preservative  of  hypodermic  solutions.  Incompatible 
with  nitrous  ether,  bromids,  iodids,  chloral  hydrate, 
phenol,  resorcin  ajid  thymol  (with  these  it  liquefies). 

Acetaniiid  should  be  carefully  tested  before  using 
in  pharmacy.  It  should  give  the  phenylisocyanid 
test,  which  distinguishes  it  from  methylacetanilid  and 
antipyrin.  A  cold,  saturated  solution  of  acetaniiid 
should  not  affect  ferric  chlorid  test  solution,  showing 
the  absence  of  anilin  salts. 

XYLIDINS  are  amido-xylenes  and  bear  the  same 
relation  to  the  three  xylenes  that  anilin  bears  to 
benzene.  They  are  difficult  of  preparation  in  the 
pure  condition,  p.  xylidin  is  made  by  reducing  p. 
nitro-xylol  with  nacent  hydrogen. 

DIAMINS. — Besides    the    monamins,    like   anilin, 

CgHg.NHg,  there  is  a  class  of  diamins,  C^/ 

NH, 


442  PHARMACEUTIC    CHEMISTRY. 

Preparation. — The  diamins  are  prepared  by  re- 
ducing the  dinitro-benzenes.  Thus,  orthoAxmiro- 
benzene  yields  orthophenylene  dianiin: 

CeH,(NQ,)3     +6H,  =  C,H,(NH,),  +  ,H,0 

o.  dinitrobenzene  o.  phenylenediamin. 

The  meta-  and  para-  varieties  are  similarly  prepared. 
O/'/Zzophenylenediamin  melts  at  102°  C.  Meta- 
phenylenediamin  melts  at  63°  C,  and  the  para-  com- 
pound melts  at  147°  C. 

Meta  phenylenediamin,  with  traces  of  nitrous  acid 
salts,  gives  intense  brown-colored  diazo  colors,  and 
hence  it  is  valued  in  water  analysis  for  the  detection  of 
nitrites. 

THE  DIAZO  COMPOUNDS. 

When  a  primary  aromatic  amin  is  treated  with  cold 
nitrous  acid,  diazohenzene  is  produced: 

CgHgNH^  +  MONO    =     CeH-^N  =  N.   OH; 

diazobenzene 

This,     when     warmed,    is    decomposed,    and    a 
hydroxy  compound  formed : 
C,H5.N  =  N.0H  +  HP  =  CaH,.QH  +  N.  +  H.,0 

diazobenzene  phenol. 

The  production  of  this  intermediate  diazo  com- 
pound distinguishes  the  aromatic  from  the  aliphatic 
amins  and  also  from  those  aromatic  amins  containing 
the — NH2  group  in  the  side  chain;  these  react  with- 
out the  intermediate  product: 

QH^.NH,  -f  HONO  =  C^H^.OH  +  N^  -f  H^O. 

ethylamin  alcohol 

THE  DIAZO  COMPOUNDS  may  be  said  to  con- 
tain two  nitrogen  atoms  for  each  phenyl  group 
(Gries,  1858). 


DIAZOBENZENE.  443 

DIAZOBENZENE  NITRATE,  CeH^— N  =  N— 
NO3,  also  called  benzene  diazonium  nitrate  (Gries, 
1866),  occurs  in  silky  crystals,  and  is  exceedingly  ex- 
plosive. It  is  produced  by  acting  with  nitrous  acid 
upon  anilin  nitrate  at  a  very  low  temperature.  It  is 
poisonous,  and  decomposes  at  ordinary  temperatures. 
A  compound  allied  to  the  above  is  diazobenzene- 
biityrate,  CgHs— N  =  N— C^HgOo,  called  tyrotox- 
icon;  found  in  fermented  ice  cream,  and  known  as 
"ice  cream  poison." 

The  cases  of  poisoning  with  tyrotoxicon  are  very 
common  in  the  summer  time. 

DIAZOBENZENE,  CeHj— N  =  N  — OH,  is  ob- 
tained by  mixing  two  very  cold  solutions,  one  of 
anilin  in  hydrochloric  acid,  the  other  of  amyl  nitrite  in 
alcohol.  A  crystalline,  colorless  body  separates 
out,  and  speedily  acquires  a  brownish  color  on 
exposure. 

Reaction  : 

CeHs.NH.+HCl  +  HONO  =  C6H,.N  =  N— C1+2H,0. 
diazobenzene 
hydroclilorid 

The  diazobenzene  sulfate  may  be  obtained  in  the 
same  way.  By  the  addition  of  potassium  hydroxid, 
a  potassium  salt  is  obtained  which  can  be  decomposed 
with  acetic  acid,  giving  the  very  unstable  diazobenzene : 

CeHg.  —  N  =  N— C1+H,0  ^CeHg  — N==N— OH+HCl 
diazobenzene  chlorid  diazobenzene 

This  is  an  unstable,  colorless,  explosive  salt.  Its 
unstable  character  is  taken  advantage  of  in  the  prep- 
aration of  other  classes  of  aromatic  compounds. 


444  PHARMACEUTIC    CHEMISTRY. 

REACTIONS  OF  THE  DIAZO  COMFOUNES. 

(i)  When  a  diazo  com])ound  is  boiled  with  water, 
it  becomes  brown,  evoh-es  nitrogen  and  forms  a 
phenol : 

C6H^.N  =  N-C1  +  H,0=C6H,.0H  +  N,+HC1. 
diazobenzene  phenol 

chlorid 

(2)  When  a  diazo-compound  is  dissolved  in 
alcohol  and  heated  for  some  time,  it  evolves  nitrogen 
and  forms  a  hydrocarbon: 

C6Hs^N  =  N-N03  +  C2H5OH  =  C6H6  +  N2  +  HNO3  +  CaH40. 
diazobenzene  nitrate  benzene 

(3)  When  a  diazo  compound,  dissolved  in  cold 
water,  is  mixed  with  cuprous  chlorid,  chlorbenzene  is 
formed.  The  copper  salt  acts  as  a  catalytic.  An 
addition  compound  of  the  copper  and  diazo  salt  first 
forms,  and  this  on  warming  regenerates  the  cuprous 
chlorid: 

{a)  C6Hs-N  =  N-Cl  +  Cu,CU  =  C6H5-N  =  N-Cl,Cu2Cl,. 
{b)  C6Hs-N  =  N-Cl,Cu.Cb-C6H5Cl  +  N,+Cu.Cl.. 
chlor- 
benzene 

(4)  W^hen  a  diazo  compound  is  heated  with 
hydrobromic,  hydrochloric  or  hydriodic  acids,  a  cor- 
responding benzene  halid  is  produced: 

C6H5-N.-N03  +  HBr  =  C6H5Br-hNa  +  HN03. 
diazobenzene  nitrate  brom- 

benzene. 

REDUCTION  OF  DIAZO  COMPOUNDS. 

When  diazobenzene  hydrochlorid  is  reduced  by 
stannous  chlorid  in  hydrochloric  acid,  it  is  converted 
into   phciiyl-hydrazin  hydrochlorid. 

PHENYLHYDRAZIN,  (\,H,,.NH.N?I,,  may  be 
said  to  be  derived  of  hvdraziii,  NH^.NH, 


THE  AZO    COMPOUNDS.  445 

Reaction: 

C6H,N,C1  +2H,    =   CeH.NH.NH^HCl. 
diazobenzene  chlorid  phenyl  hydrazin 

hydrochlorid. 

This  salt  is  decomposed  with  potassium  hydroxid, 
and  phenylhydrazin  is  taken  up  and  crystallized  from 
ether.  It  is  slightly  soluble  in  water,  but  freely 
soluble  in  the  organic  solvents. 

Its  action  upon   the   ketones  and  aldehyds   has 
been  described  under  the  "  Carbohydrates."    By  this 
means  we  are  able  to   separate  these  compounds 
from  their  mixtures  in  the  pure  state;  thus: 
CeHs-CHO  +  H.N.NH.CeH,^ 

benzaldehyd  phenylhydrazin 

C6H5.CH:N.NHCeH5  +  H20 

benzaldehyd  phenylhy- 
drazone. 

This  salt  can  be  hydrolyzed  by  boiling  with  dilute 
acids  into  phenylhydrazin  and  the  pure  aldehyd 
(or  ketone,  as  the  case  may  be)  is  thus  obtained: 

^  \H. 


Structure: 


THE  AZO  COMPOUNDS. 

When  nitrobenzenes  are  reduced  in  acid  solutions 
corresponding  amins  are  formed.  When,  however, 
the  nitro-derivatives  are  reduced  in  aJkaJin  solutions 
with  zinc  dust,  azo  compounds  result.     Thus,  nitro- 


446  PHARMACEUTIC    CHEMISTRY. 

benzene,  dissolved  in  a  solution  of  sodium  hydroxid, 

will  give: 

2CeH,.N03  +  2H,  =  CeH,-N=N-CeHs  +  2H3  =  H3 

azobenzene. 

As  Stated  under  Diazobenzenes,  they  are  com- 
pounds containing  two  nitrogens  for  each  phenyl; 
the  azo  compounds  contain  two  nitrogens  to  two 
phenyl  groups. 

AZOBENZENE,  CgH^— N  =  N— CgH^,  crystallizes 
in  red  tablets,  melting  at  94°  C,  and  subliming  at 
293°  C.  By  further  reduction,  hydrazobenzene, 
CeHjNH— NH— C0H5,  is  produced. 

The  higher  and  more  complex  azo  compounds 
are  all  highly  colored,  and  much  valued  as  dyes. 

Hydrazobenzene  oxidizes  in  the  air  turning 
orange  color  and  forming  azobenzene.  By  boiling 
with  strong  hydrochloric  acid,  amino  azobenzene 
IS  formed. 

BENZIDINE,  aminoazobenzene,  diaminodiphenyl, 
is  a  strong  base,  Ci2Hg(NH2)2,  a  very  important  sub- 
stance in  the  preparation  of  benzidine  dyes: 


-NH— NH 


hydrazobenzene 

H.N<~~~>-<  >NH.. 

benzidine 

Of  the  important  benzidine  dyes,  the  following 
mav  I)e  mentioned: 

CHRYSAMIN,  made  by  acting  with  sodium 
salicvlate  upon  diphenyltetrazochlorid: 


DIAZO-AMIDO   COMPOUNDS.  447 

\C00Na 


/OH  /OH 

CeH^N.Cl  +  C6H4/  C6H4.N,.C6H3/ 

\COONa 


OH 


+  2HCI. 
OH 


C6H4N3CI+C6H   /  C6H4.N2.C6H3< 

\COONa  \COONa 


chrysamine 

;03Na^ 


CONGO-RED  =  (CeH,.N2.C,oH,/ -^^^3^^) 
'NH, 


N    =    N  r    T-T 

I  I 
\/ 
/\ 
I       I 


BIEBRICH  SCARLET 

►3I 


i       I 


The  benzidine  dyes  can  be  used  in  dye'ng  cotton 
\  ithout  a  mordant. 

THE  DIAZO-AMIDO  COMPOUNDS. 

This  series  of  compounds  is  formed  by  adding  an 
amido  to  a  diazo  compound.  These  compounds, 
upon  standing,  are  transformed  into  AZO-AMIDO 
COMPOUNDS. 

DIAZOAMIDOBENZENE   is  obtained   as  follows: 

CeH.N.Cl    +    NH.CeH,    =    C6H,N,.NH.C6H,  +  HCl. 
diazobenzene  anilin  diazoamidobenzene 

chlorid 

29 


448 


I'llARiMACEUTlC    CHEMISTRY. 


This   compound   occurs   in   golden-yellow    prisms 
which,  when  heated  with  anilin,  yield: 
AMIDOAZOBENZENE, 

C«H,.N,,.NH.C«H,  -^  C«H3.N,.C„H,.NH,. 
Structures  oj  the  two: 
H 

/\  I         /\  /\  /\ 

-N=N- 


-N  =  N-N- 


I       I 
I       I 


1  r 
I  I 
\/ 


1    I 
I    I 


-NHj 


diazoamidobenzene 


amidoazobenzene 

THE  HYDROXYAZO-BENZENES  are  formed  from 
phenol  and  a  diazo  compound.  Like  the  amido- 
azo  benzene,  they  form  valuable  dyes,  of  which  those 
derived  from  para-amidosulfonic  acid — are  mostly 
valued,  in  that  they  dye  silks  and  wool  without  a 
mordant.     Structure: 


-N  =  N— 


I       I 
I       I 


OH. 


The   rchitiouship  oj  the   iiiiro  compounds   is  best 
;hown  by  the  following  structural  formulas: 

^0  (2)  M 


— N  =  N— NO3 


N:H, 


diazobenzene 
nitrate 


phenyl  hvdrazin 


HYDROXY    BENZENES. 

(3)        H 

-N  =  N— N— 


449 


diazoamidobenzene 

(4) 


amidoazobenzene 

(5) 

_N  =  N— 


-NH, 


-O— H 


h  ydroxyazoben  z  en  e 


HYDROXY    BENZENES. 

There  are  three  classes  of  hydroxy  benzenes: 
those  containing  one  hydroxyl  —OH  group  known 
as  phenols,  those  containing  two  hydroxyh,  known 
as  diatomic  or  dihydroxyphenols,  and  with  three 
hydroxyls,  the  triatomic  phenols.  The  monatomic 
phenols  have  no  isomers,  but  the  diatomic  phenols 
each  have  three  isomers. 

There   are   two   kinds   of   hydroxyderivatives   of 


450  PHARMACEUTIC    CHEMISTRY. 

the  aromatic  hydrocarbons:  those  in  which  the 
hydroxy!  group  is  substituted  for  the  hydrogen  of  the 
nucleus  and  those  in  which  the  substitution  takes 
place  in  the  side  chain.  The  first  kind  are  known 
as  phenols,  the  last  as  aromatic  alcohols. 

Preparation. — (i)  By  fusion  of  sulfonic  acids 
with  potassium  hydroxid: 

C^Hs.SOg.K  +  KOH=  CeHs  — OH  +  KjSOg. 

potassium  benzol  phenol 

sulfonate 

(2)  By  prolonged  boiling  of  diazobenzene  chlorid 
with  water: 
CfiHs.N^  —  CI  +  H.O  =  C,H,.OH  +  N^  +  HCl. 

diazobenzene  phenol 

chlorid 

Properties. — The  phenols  contain  the  tertiary 
alcohol  group  =C — OH,  and  therefore  appear  to  be 
allied  to  the  tertiary  alcohols;  and  in  reality  they  are 
acted  upon  similarly  by  the  oxidizing  agents.  Like 
alcohols,  the  phenols  form  ethers  and  esters;  and, 
as  stated  above,  they  may  be  monacid  (CgH^-OH), 
diacid  (C6H^(OH)2),  or  triacid  (C8H3(OH)3). 

Phenols  and  the  aromatic  alcohols  are  isomeric, 
I)ut  possess  entirely  different  properties. 

PHENOL,  C,H^OU,  phenol,  phenic  acid,  phen>l 
alcohol,  phenyl  hydrate  (acidum  carbolicum  U.  S.  P. 
'90).  Chemically,  it  is  not  an  acid-,  but  a  phenol 
or  hydroxy  benzene,  hence  the  change  in  pharmaco- 
])(x;ial  name.  Purity,  96%.  Phenol  resembles  crea- 
sote  in  its  odor  and  caustic  ])ro])erties,  but  differs  in 
chemical  composition  in  being  a  solid  at  ordinary 
temperatures.     Melting-point,    40°.     It    is   soluble 


PHENOL  AND    PREPARATIONS.  45 1 

in  9.6  parts  water  (creasote  in  140  parts  water). 
Boiling-point,  100°  C.  Insoluble  in  benzin,  and 
coagulates  collodion  when  mixed  with  it. 

Phenol  liquejactum,  liquefied  phenol.  Strength, 
86.4%  of  phenol,  13.6%  of  water.  Prepared  by 
melting  phenol  in  an  unstoppered  bottle  on  a  water- 
bath  and  mixing  it  with  10%  of  its  weight  of  distilled 
water.  By  using  alcohol  instead  of  water,  corking 
the  bottle  and  placing  "upside  down,"  solution  may 
be  effected  without  heat.  Dose,  i  gr.,  largely 
diluted.  It  is  a  caustic  and  deadly  poison.  Alcohol 
prevents  its  caustic  effect,  and  should  be  first  admin- 
istered, followed  by  large  doses  of  magnesium  sulfate 
in  solution,  which  forms  a  harmless  sulfocarbolate 
of  magnesium.  Preparations:  Unguentum  phen- 
olis  (3%);  glyceritum  (liquefied  phenol,  20  %). 
Used  as  a  disinfectant  and  antiseptic  dressing.  Car- 
bolic lotion  is  prepared  by  dissolving  one  part  of  the 
acid  in  30  parts  hot  water  (carbolized  water). 

Note. — Observe  that  the  solution  of  phenol  is  of 
5%  strength,  while  liquefied  phenol  is  86.4%. 

Tests. — With  ferric  chlorid,  dilute  solutions  of 
phenol  are  colored  violet. 

With  bromin  water  a  precipitate  of  tribromphenol 
is  produced.  This  is  known  as  hromal,  CgHjBrgOH, 
upon  the  formation  of  which  the  phenol  assay  method 
depends. 

PHENOL  ETHERS.— There  are  many  valuable 
ethers  and  esters  of  phenol,  many  of  which  replace 
the  natural  odors  of  the  flowers. 

PHENYLMETHYL  ETHER,  CgHj.O.CHg,  is  called 


452  IMfARMACEUTIC    CHEMISTRY. 

anisol.  It  can  be  obaincd  from  anisic  acid  (methoxy- 
benzoic  acid)  by  boiling  with  barium  hydroxid, 
or  by  synthesis  from  potassium  phenolate  with 
an  alkvl  halid: 

C«H,  — OK  +  CHJ  =  CfiH5^aCH3^+  KI 

potassium  anisol 

phenolate 

ETHYLPHENYL  ETHER,  or  phenetol,  is  CoH^- 
— O — QHj,  and  can  be  produced  ))y  the  above 
method,  using  an  ethyl  halid. 

DIPHENYL  ETHER,  CgHs.O.CeH^,  resembles 
the  ethyl  ether.     Among  the  esters  we  may  mention: 

PHENYL  ACETATE,  CyH5O.CO.CH3,  can  be 
obtained  by  treating  i)henol  with  acetyl  chlorid. 

OTHER  DERIVATIVES  OF  PHENOL. 

THE  PHENOL  SULFONIC  ACIDS.— W  hen  phenol 
is  dissolved  in  concentrated  sulfuric  acid,  upon 
warming,  a  mixture  of  ortho-  and  para-sulionic  acids 
is  formed.  These  are  colorless,  deliquescent,  crystal- 
line bodies,  which,  when  fused  with  potassium 
hydroxid,  yield  corresponding  diatomic  phenols. 

Phenolsulfonic  acids  are  variously  known  as  sitljo- 
carbolic  or  sozolic  acids,  also  as  aseptol,  and  have 

/C0H5OH. 
the  formula  SO, 

\()IT 

Preparation. — By  dissolving  phenol  in  strong 
sulfuric  acid: 

C„H,.OH  +  H,SO,  =  C.,H,.0H.HS03  +  H.,0. 

phenolsulfonic  acid. 

Used  as  an  antiseptic  wash  in  109^.  acjueous  solu- 
tions. 


THE    NITRO-PHENOLS.  453 

SODIUM  PHENOLSULFONATE,  sodii  phenol- 
sulfonas  (sulfocarbolas,  '90 j,  sodium  sulfocarbolate, 
NaSOg— CeH^.OH,  is  prepared  by  acting  with 
phenosulfonic  acid  on  sodium  carljonate;  a  white, 
crystalline,  soluble  salt. 

SODIUM  ICHTHYO-SULFONIC  ACID,  ichthyol, 
also  ammonium  ichthyo  sidjonate,  obtained  by 
destructive  distillation  of  bituminous  shale  found  in 
Tyrolean  Mountains.  Undoubtedly  obtained  from 
fossilized  aquatic  animals  by  dry  distillation.  A 
dark  oily  distillate  is  obtained  which,  treated  with 
an  excess  of  sulfuric  acid,  yields  ichthyolsulfonic 
acid.  This  latter  product  is  purified  and  neutralized 
with  ammonia  or  sodium  hydroxid,  yielding,  corres- 
pondingly, the  ammonium  or  sodium  salt.  The 
substance  contains  about  10%  of  sulfur.  It  is 
soluble  in  water,  glycerin  and  the  oils,  also  in  a 
mixture  of  alcohol  and  ether.  Used  in  skin  and 
rheumatic  affections,  also  in  lung  affections,  exhibited 
in  keratin-coated  capsules.     Formula^  C28H3gS30g. 

NO2 

THE    NITRO    PHENOLS,     CJ:l^(^         .    When 

dilute  nitric  acid  acts  upon  phenol,  ortho-  and  para- 
mononitro  phenols  are  yielded.  These  are  separated 
by  steam  distillation,  the  or tho nit ro phenol  being 
volatilized. 

ORTHO-NITROPHENOL  is  slightly  soluble  in 
water,  readily  in  the  organic  solvents.  It  occurs  in 
canary-yellow  crystals,  melting  at  45  °  C. 

PARA-NITROPHENOL  occurs  in  colorless  needles, 


454  IMIARMACEUTIC    CHEMISTRY. 

melting  at  114°  C;  also  soluble  in  water  to  a  small 
extent. 

(OH) 
TRINITROPHENOL  C ,U^(^  (i,    2,    4,    6), 

(N02)3 

picric  or  carbazotic  acid,  is  formed  very  easily  when 
strong  nitric  acid  acts  upon  phenol.  This  is  best 
done  in  the  presence  of  sulfuric  acid.  This  acid  also 
results  from  the  action  of  strong  nitric  acid  on 
various  substances  such  as  wool,  silk,  resin,  and 
indeed,  the  yellow  stains  upon  the  hands  produced 
by  strong  nitric  acid  are  due  to  picric  acid. 

Picric  acid  occurs  in  brilliant  yellow  crystals, 
melting  at  123°  C;  soluble  in  hot  water,  and  rede- 
positing  as  the  solution  cools.  It  explodes  under  per- 
cussion and  is  extensively  used  for  this  purpose  under 
the  name  lyddite.  Ammonium  picrate,  C6H2(N02)3.- 
O.NH^;  is  also  used  in  explosives. 

Picric  acid  possesses  acidic  properties  and 
readily  forms  salts.  It  is  a  good  yellow  dye  for  wool 
and  silk,  but  the  color  is  affected  by  light.  It  will 
not  dye  cotton,  and  thereby  forms  a  reliable  test  for 
its  detection  in  mixed  goods. 

PHENYL  MERCAPTAN,  CeH^.SH,  phenyl  hydro- 
siilfid,  thiophenol,  bears  the  same  relation  to  phenol 
that  mercaptan  does  to  alcohol.       It  can  be  pre- 
pared bv  reducing  benzcnc-sulfonic  acid. 
/CH, 

THE  CRESOLS,  C„H,(^  ,   or    methyl  phenols. 

OH 
cresvlic   acids,    hvdroxv    toluols.     There    are    three 


CREASOTE. 


455 


isomeric  cresols,  all  found  in  pine- and  coal-tars; 
they  are  similar  to  phenol.  To  obtain  pure  cresols, 
it  is  best  to  prepare  these  from  the  three  toluidins. 

CRESOL,  C7H7OH  (Duclos,  1859),  formerly 
known  as  cresylic  acid,  a  mixture  of  three  isomeric 
cresols  is  obtained  from  coal-tar  and  separated  from 
phenol  by  fractional  distillation.  It  is  a  refractive 
liquid  of  a  strong,  phenol-like  odor,  colorless,  but 
becoming  brown  on  exposure,  soluble  in  60  parts 
water  and  all  other  solvents.  Used  as  disinfectant 
and  deodorant.  One  to  5%  solutions  are  more 
certain  antiseptics  than  phenol  minus  its  poisonous 
properties.  Creolin,  lysol,  are  preparations  similar 
to  Liquor  cresolis  compositus,  a  5o'>(,  solution  of 
cresol  in  soft  soap. 

CH,  CH,  CH, 


OH 


OH 


orthocresol  melting- 
point  3 1°  C. 


metacresoi   melt- 
ing-point 4°  C. 


OH 


paracresol  melt- 
ing-point 36°  C. 


CREASOTE  is  a  mixture  of  phenols,  cresols  and 
guaiacol,  obtained  from  wood  (fagus  silvatica),  tar. 
There  is  also  coal-tar  creasote  in  commerce,  which 
consists  largely  of  phenol. 

CREASOTUM.— A  mixture  of  several  substances 
belonging  to  the  class  known  as  phenols.  It  is  ob- 
tained by  distilling  wood-tar,  preferably  that  from 


456  PHARMACEUTIC    CHEMISTRY. 

beechwood.  Boiling-point  above  200°  C. ;  consisting 
chiefly  of  guaiacol  (C^HgO,)  and  cresol  (C^HjoOz). 
The  distillate  from  tar  separates  into  two  layers; 
the  heavier  one  is  freed  from  impurities  by  treatment 
alternately  with  KOH  and  HjSO^,  and  the  portion 
boiling  between  200°  and  220°  C.  is  separated  by 
fractional  distillation.  An  almost  colorless,  oily 
liquid,  of  a  penetrating,  smoky  odor  and  a  burning, 
caustic  taste,  darkening  on  age;  gelatinizes  but  does 
not  solidify  at  the  freezing-point  (difference  from 
phenol).  It  is  intlammable,  burning  with  a  smoky 
flame.  It  coagulates  the  albumin  of  the  skin,  pro- 
ducing a  white  stain.  It  is  neutral.  Specifac 
gravity,  1.07.  Soluble  in  140  parts  water  (phenol 
in  19.6  parts  water).  It  is  soluble  in  benzin  and 
does  not  coagulate  collodion  (difference  from 
phenol).  It  is  also  soluble  in  alcohol,  ether,  chloro- 
form, fixed  and  volatile  oils.  Used  to  deaden  pain 
and  preserve  tissue,  as  an  application  in  toothache; 
internally  to  allay  nausea;  in  consumption  and  lung 
diseases.  Preparation:  Aqua  creasoti  (a  saturated 
solution). 

GUAIACOL,  CyHgOs-  Guaiacol,  the  chief  con- 
stituent of  creasote  (85%),  is  obtained  by  purification 
and  fractional  distillation.  Synthetically,  by  methy- 
lization  of  catechol.  A  colorless,  refractive  liquid, 
of  an  agreeable,  aromatic  odor;  specific  gravity,  1.14; 
or  a  crystalline  solid  melting  at  28.5  C.  Soluble  in 
53  parts  water,  in  alcohol  and  ether  in  all  propor- 
tions, and  in  i  part  glycerin.  Used  as  substitute  for 
creasote    in    tuberculosis,    in    eli.xirs,     .syrui:)s     oils, 


C.UAIACOL    CARBONATE   AND    THYMOL.  457 

emulsions  and  in  capsules.     Chemically,  it  is  mono- 

,         ,         ..     TT  /O  — CH3 

methyl  pyrocatechol,  C-eH^  < 

GUAIACOL  CARBONATE,  guaiacolis  carbonas, 
(C7H70)X03.  Obtained  by  the  action  of  carbonyl 
chlorid  on  sodium  guaiacolate.  An  almost  tasteless, 
odorless,  white,  crystalline  powder,  insoluble  in  water; 
soluble  in  48  parts  alcohol;  in  1.5  parts  chloroform; 
slightly  in  ether.  Used  as  guaiacol  ip  tuberculosis 
in  powder  form.      Chemically,  it  is  di-monomethyl 

(CpH-.CHg.Ox^^    ^ 
CH   CH   0/        ') 
Among  the  higher  monatomic  phenols,  we  have 
thymol  and  carvacrol. 

CH3     (1) 
THYMOL,— CgHg— OH     (2),  propylmetacresol, 
^C3H,  (4) 
is  a  phenol  occurring  together  with  cymene  in  the 
oil    of    thyme.     It    can    be    synthetically    prepared 
from  nitrocuminic  aldehyd,    CgHg — CHO — NOj — 
C3H7  (1,3,  4).     Thymol  forms  large  monoclinic  crys- 
tals, melting  at  50°,  its  odor  reminds  one  of  thyme, 
it  is  one  of  the  two  possible  hydroxy  derivatives  of 
cymene,  the  other  being  carvacrol,  which  has  also 
been  obtained  from  the  oil  of  carawav: 
CH,  CH, 


OH 


OH 


C3H,  C3H, 

thymol,  melting-  carvacrol,  boiling- 

point,  50°  point,  236° 


458 


PHARMACEUTIC    CHEMISTRY. 


AMIDOPHENOLS,     C,H. 


OH 


are  produced 


xNH, 

by  reducing  the  corresponding  nitrophenols  with 
hydrogen.  They  occur  as  colorless  crystalline 
substances,  basic  in  character.  Meta-amido phenol 
forms  the  basis  of  some  of  the  rhodamin  dyes. 

Para-amido phenol  is  a  solid,  melting  at  184°,  and 
yielding  an  ethyl  ether  paraphenetidin, 
CgH^^f  2&    ■\  this  is  converted   by   glacial  acetic 

acid  into  an  acetyl  derivative  phenacetin. 

PHENACETIN  (acetphenelidinum),  CeH^.NH.Q- 
HgO. (QH^O) .  A  phenol  derivative  made  by  acetaliz- 
ing  para-amidophenetol.  Chemically,  para-acetic- 
phenetidin.  White,  crystalline  scales  or  powder, 
odorless,  tasteless.  Soluble  in  925  parts  water,  12 
parts  alcohol,  also  ether  and  chloroform.  Used  as 
analgesic  and  antipyretic  in  powders  or  capsules. 
It  melts  at  134°  C,  should  not  give  precipitate  with 
bromin  water  (acetanilid). 

Preparation. — From  para-nitrophenol,  by  convert- 
ing it  into  nitrophenylethyl  ether,  this  reduced  w-ith 
hvdrogen  to  form  para-amidophenol,  this  acetylated 
bv  boiling  with  glacial  acetic  acid;  thus: 

OH  O.QH.,       O.QH5       O.C2H5 


NO, 


NO. 


para-nitio- 
phenol 


para-nitro- 
phenol ethyl 
ether 


_NH2 

para-amido- 
phenetol 


NHCHgO 

para-acetamino- 

phenetol  (acet. 

phenetidin) 


LACTOPHENIN,    HOLOCAIN,    PHENOCOLL.         459 

If,  instead  of  acetic  acid,  lactic  acid  be  employed 
in  the  last  reaction: 
LACTOPHENIN,  C.H.(NH^C.H,0„isproduced. 

Both  are  used  as  antipyretics. 

Two  other  derivatives  of  para-aniido — phenol  are: 

O.C3H, 
HOLOCAIN,  CfiH  / 

and  ^0,H, 

PHENOCOLL,  C,h/2h.CO.CH,NH,  =  ^^^^°- 
acetic  acid  derivative. 


CHAPTER  XXXV. 


DIATOMIC  PHENOLS. 

There  are  three  isomeric  diatomic  (diacid) 
phenols.  They  are  produced  by  fusing  together 
the  disulfonic  acids  with  potassium  hydroxid. 
They  occur  in  horses'  urine  (pyrocatechin),  and  in 
human  urine  (hydroquinon)  after  administration  of 
phenol;  resorcinol  is  obtained  by  melting  galbanum, 
asafetida  and  other  resins: 

OH  OH  OH 


OH 


I        I 

I        1 


OH 


OH 


ortho-dihyd/oxy- 

benzene    catechol 

(pyrocatechin) 

melting-point, 

104°  C. 


meta  -  dihydroxy- 
benzene  resorcinol 
(resorcin)  melting- 
point,   119°  C. 


para-dihydroxy- 

benzene  quinol 

(hydroquinone) 

melting-point, 

169°  C. 

CATECHOL,  pyrocatechin,  C«H,(OH).,,  (1.2), 
occurs  in  nature  in  cutch,  from  which  it  derived  its 
name,  in  kino,  and  obtained  by  the  fusion  of  many 
gums  with  the  alkalis. 

It  is  a  colorless  crystalline  solid,  soluble  in  water 

and  in  other  solvents.     Its  solutions  in  alkali  hydro.xids 

absorb  oxvgen  from  the  air  and  ra])idly  l)CComc  brown. 

Willi  ferric  chloric!  its  solutions  are  colored  green  — 

460 


RESORCINOL,    FLUORESCEIN,    EOSIN.  46 1 

this  being  characteristic  of  all  the  urtho-dihyclroxy 
phenols. 

When  catechol  is  treattd  with  methyl  iodic! ,  mono- 
methyl  ether  of  catechol,  guaiacoJ,  CgH^(^  OCH     ^^ 

produced. 

RESORCINOL  (resorcinum),  C^Yi^^OU),^,  (1.3), 
resorcin,  a  diatomic  phenol  (metadih3'droxy  benzene). 
Obtained  by  action  of  alkalis  on  metabenzene 
disulfonates.  Faintly  reddish  crystals;  very  soluble 
in  alcohol  and  water.  Melting-point,  110°  to  iii°C. 
Used  as  antiseptic,  antiseborrheic  in  solutions, 
ointments,  etc.  Incompatible  with  ferric  chlorid 
(violet  color);  with  hypochlorite  solutions  (violet  to 
yellow),  with  spirit  of  nitrous  ether  (dark  red);  on 
trituration,  it  liquefies  or  softens  with  phenol, 
menthol,  camphor,  chloral  hydrate,  acetanilid,  anti- 
pyrin,  etc. 

With  phthalic  anhydrid,  when  heated,  resorcin 
forms  a  brown  substance,  which  is  soluble  in  caustic 
alkalis.  The  alkali  solution  of  the  body  added 
to  water  produces  brilliant  green  fluorescence,  and 
hence  the  name  of — 

FLUORESCEIN,  QoHi^O^,  resorcin-phthalein,  has 
/CeH3(0H), 
the  structure  C— C6H3(OH),  ,  and  is  mostly  used  in 
^CeH,C  =  0 

I 
O 


the  making  of — 

EOSIN  or  tetrabromfluorescein  pink  dyes.     When 
fluorescein  is  acted  upon  by  bromin  in  acetic  acid 


462  PHARMACEUTIC    CHEMISTRY. 

solution,  eosins  are  produced.     The  ordinary  eosin 
dve  is  the  sodium  salt  of  tetrabromfluorescein: 
/C„HBr,ONa. 


C«H  /       O 


CeHBr^ONa. 

c=o 


PHENOLPHTHALEIN  is  obtained  by  heating  one 
molecule  of  phthalic  anhydrid  with  two  molecules 
of  phenol  to  115°  C.     With  the  addition  of  strong 
sulfuric  acid,  phenolphthalein  is  formed.     It  occurs 
as  a  white,  crystalline  substance,  melting  at  251°; 
slightly  soluble   in   water,   but   soluble   in   alcohol. 
It   constitutes   a   valuable   indicator   in    volumetric 
analysis,  turning  pink  with  alkalis. 
Slrurture,       /CgH^OH 
C— C„H,OH. 
C«H,.CO 


phenol 
phthalein. 

RHODAMINES  constitute  some  of  the  best  brilliant 
red  dyes.  They  are  obtained  from  meta-amido- 
phenol  and  ])hthalic  anhvdrid.     Structure, 

'^/'CJI,.NH, 

^  0 


c 

I   ^C„H3.NH, 


AURIN,    ROSOLIC   ACID,    INDIGO. 


463 


AURIN  is  prepared  by  heating  together  phenol 
and  oxalic  acid  in  presence  of  strong  sulfuric  acid. 

ROSOLIC  ACID  is  prepared  from  a  mixture  of 
phenol,  cresol  and  arsenic  acid  in  presence  of  a 
dehydrating  agent.  Both  the  above  dyes  are  struc- 
turally represented — 


C^C,H,OH 

aurin 


CeH3(CH3)OH 


INDIGO,  one  of  the  most  valuable  blue  dyes,  is 
obtained  from  the  leaves  of  the  indigo  plant  (indigo- 
fera  tinctoria),  indigenous  to  India.  Commercial 
indigo  is  not  the  pure  substance,  but  a  mixture  of 
varying  quantities  of  other  coloring  matters,  as 
indigo  brown,  indiruhin,  etc.  It  can  be  purified  by 
crystallizing  it  from  anilin,  and  as  such  it  is  known 
as  indigotin  or  ^^ pure  indigo.''^ 

Indigo  synthesis  has  taken  up  the  chemist's  atten- 
tion for  many  years.  It  is  now  prepared  synthetic- 
ally by  one  of  two  following  methods: 

(i)  From  ortho-nitrobenzaldehyd  and  acetone 
with  dilute  sodium  hydroxid  solution: 

CHO 

4-    2C  =  o 

I  "^CH, 

CteHtoN^O^  +  2CH3COOH  +  2H3O. 


30 


464  PHARMACEUTIC    CHEMISTRY. 

(2)  From  anthranilic  and  chloracetic  acid  forming 
phenyl-glycine  o-carboxylic  acid;  the  process  consists 
of  two  steps: 

(a)  /COOH  /C(OH)\ 

CeH/                     =C6H4<                )CH  +  CO.+  H,0. 
Xnh.ch.cqoh     \  NH  / 

Phenyl-glycine  o-carboxylic  indoxyl. 

acid 

(b)  /C(OH)v 

2C6H/  )CH  +  O.     = 

\    NH    / 

C6H4/  >C  =  C<  >C6H4-t-2H.O. 

Xnh/         \nh/ 

indigo. 

MALACHITE  GREEN,  benzaldehyd  green,  is  made 
by  heating  together  benzaldehyd,  dimethyl  anilin 
and  zinc  chlorid.  This  forms  the  water-insoluble, 
colorless  leuco-hase, 

H— C^CeH,.N(CH,), 
\C6H,i\(CIT.,)3 

leuco-base 

this,  oxidized  with  lead  peroxid  and  HCl,  gives 

Cl.cf-CeH.N.CCH^)^ 
^C,H.N.(CH3)3 

malachite  green. 

ROSANILIN,  also  called  fuchsin  and  niat^cnta, 
was  originally  oinaincd  by  heating  anilin  and  ])ara- 
toluidin  with  arsenic.  It  was  one  of  the  first  dyes 
produced. 

The  product  is  magenta  arsenate,  which,  on  addi- 


ANILIX  AND    METHYLP:NE    BLUES.  465 

tion  of  sodium  chlorid,  is  converted  into  the  hydro- 
chlorid. 

Structure,  C(CeH,.NH2)2 

C 
HC^>iCH 


HCll    llCH 


NH.HCl 


para-rosanilm- 
hydrochlorid. 


ANILIN  BLUE  is  obtained  from  rosanilin  by 
heating  it  with  anilin  and  acetic  acid.  Each  of  the 
three  amino  groups  loses  one  hydrogen  atom  which  is 
replaced  by  a  phenyl-group: 

C  ^—C  H  N/^H 


triphenyl  rosanilin  hydrochlorid 
(anilin  blue). 


METHYLTHIONIN  HYDROCHLORID  is- 

/C.H,/N(CH,), 


N  ? 

\  ^ 

methylene-biue. 


466 


PHARMACEUTIC    CHEMISTRY. 


CRYSTAL  VIOLET  is  the  hexamethyl  derivative 
of  para-rosanilin.     It  has  the  structure 
/CH3 


-CeH,.N 


CgH^.N 


CH3 
.CH3 

CH3 
/CH3 

I  VH3 


\ 


crystal  violet. 

METHYL  VIOLET  has  the  structure 
•  /C,H,N(CH3)3 
Cf  CeH,N(CH3)3 
I    \C6H,NCH3HC1 


pyoktanin 

The  above  dyes,  with  the  exception  of  indigo, 
may  be  said  to  be  derivatives  of  tri  phenyl  methane, 

H.C^CeH,. 

Many  other  important  dyes  are  known,  Init  of 
less  interest  to  the  pharmaceutic  student  than  the 
above  types. 


OH 


CREOSOL,   methyl  dioxytoluene, 


OCH3 
CH, 


occurs  m  creasote. 


QUINOL  AND    ORCINOL.  467 

QUINOL,  CyHj(OH).,,  hydroquinon,  hydroquinon 
is  usually  made  by  reducing  quinon  or  by  fusing 
paraiodophenol  with  potassium  hydroxid.  It  oc- 
curs in  leaflets  or  prisms  melting  at  169°  C; 
soluble  in  water.  Its  alkalin  solutions  absorb 
oxygen  from  the  air.  It  is  used  for  the  above  reason 
in  photography  as  a  reducing  agent.  By  oxidizing 
hydroquinon  quinon  is  produced,  C 611^02;  with 
two  molecules  of  hydroxylamin  it  forms  quinon- 
dioxime, 

O  N— OH 

/\ 

II     II       _^ 


O  N— OH 

ORCINOL,  dihydroxytoluene,  C6H3CH3(OH)2,  can 
be  conveniently  classed  with  the  dihydroxyphenols. 
Orcinol  is  obtained  from  several  varieties  of  lichens, 
artificially  by  melting  chlortoluene  sulfonic  acid  with 
potassium  hydroxid.  It  occurs  in  colorless  prisms 
which  turn  red  on  exposure,  and  with  ferric  chlorid, 
deep  blue. 

Orcinol  treated  with  ammonia  is  converted  into 
orcein,  CjgHj^NjOy,  which  with  alkalis  gives  a  red 
dye.     This  is  the  chief  use  of  orcin. 

Orcin  is  closely  related  to  archil,  litmus  and  cud- 
bear, three  dye-stuffs,  all  prepared  from  the  lichens 
by  macerating  them  with  urine  which,  when  decom- 
posed, yields  ammonia,  and  this  develops  the 
coloring  principles. 


468  PHARMACEUTIC   CHEMISTRY. 

DYEING. 

Having  mentioned  the  important  dyes,  a  discussion 
of  dyeing  should  prove  interesting  and  instructive. 

It  has  been  stated  that  a  large  part  of  the  economic 
value  of  coal-tar  products  consists  in  the  dyes  made 
therefrom. 

Thus,  the  important  "Turkey-red"  from  madder, 
"indigo"  from  the  indigo  plant  of  India  and  "log- 
wood black"  from  logwood,  have  all  been  replaced 
by  the  corresponding  alizarin  from  anthracene,  indigo 
from  naphthalene  and  nigrosin  from  anilin. 

Likewise  the  number  of  plant  dyes  are  limited 
while  the  artificial  dyes  are  almost  numberless  and 
constantly  increasing  in  number. 

DYES  are  frequently  classified  in  two  ways: 

(a)  Into  substantive  dyes,  which  color  fabrics  with- 
out a  mordant,  and  objective  dyes,  which  color  fabrics 
with  mordants  only. 

(b)  Into  basic  dyes,  usually  a  hydrochlorid  of  an 
aromatic  amid,  and  acid  dyes,  the  sodium  salts  of  a 
sulfonic  aromatic  acid. 

MORDANTS  (from  Latin  mordere,  to  bite  in),  a:e 
substances  like  albumin,  which  combine  with  dyes, 
making  double  compounds;  and  with  the  basic  dyes, 
acids,  like  tannic,  or  salts,  like  stannic  chlorid  and 
tartar  emetic,  precipitate  in  the  fiber  of  the  fabric 
insoluble  lakes.  Mordants,  therefore,  are  sub- 
stances which  fix  colors  on  fabrics. 

THE  FIBERS  USED  can  be  divided  into  animal 
or  vegetable. 

The  animal  fibers  embrace  wool,  the  hair  of  sheep; 


DYEING.  469 

hair  of  goats  and  camel,  etc.;  silk,  the  libers  from 
which  the  cocoons  of  the  silk-worm  are  spun; 
feathers  of  the  various  fowl,  etc. 

The  vegetable  fibers  embrace  cotton,  chiefly  pure 
cellulose;  jute,  the  hemp  fiber;  linen,  the  flax  fiber; 
straw,  esparto,  etc. 

PREPARATION  OF  THE  FIBERS.— The  fibers 
are  generally  washed  to  remove  coloring  material, 
grease,  wax  and  dirt.  This  is  frequently  done  by 
boiling  with  lime  or  soda-ash.  These  alkalis 
should,  however,  be  used  in  moderation,  excess 
weakens  the  fiber. 

The  fibers,  washed  free  from  the  alkali,  are  next 
bleached.  This  is  effected  by  the  use  of  solutions  of 
bleaching  powder,  Ca(Cl20)  or  sodium  hypochlorite, 
NaClO.  Potassium  permanganate  solutions  fol- 
lowed by  thiosulfates  are  also  used.  Wool  contains 
about  50%  of  its  weight  of  a  fatty  suint,  or  residue 
from  evaporated  perspiration,  which  must  be  freed 
by  boiling  it  with  alkalis. 

Wool  and  silk  can  be  bleached  with  sulfur  dioxid. 

Bleaching  is  necessary  in  almost  every  case  to 
prevent  the  impairment  of  the  color  produced  in  the 
subsequent  dyeing. 

Dyeing  consists  in  macerating  the  skeins  of  threads 
or  pieces  of  the  finished  fabric  in  an  acid  or  alkalin 
bath  containing  the  dye.  Almost  all  the  colors  have 
affinity  for  wool  and  silk,  and  no  mordants  are 
necessary.  Not  so  with  cotton;  so  few  dyes  affect 
cotton  that  invariably  mordants  must  be  employed. 

A  dye  must  of  necessity  be  a  colored  substance,  but 


470  I'lIARMACF.UTK     CHEMISTRY. 

not  all  colored  substances  are  necessarily  dyes, 
unless  they  can  i\x  themselves  to  the  fabric  in  such  a 
way  that  washing  or  rubbing  cannot  remove  them. 
Thus,  azobenzcne  is  highly  colored,  but  it  will  not 
dye  fabrics.  Likewise  wdien  silk  or  wool  are  placed 
in  a  solution  of  picric  acid,  they  will  be  dyed  a 
beautiful  yellow;  calico  or  other  cotton  material  will 
also  be  colored  yellow;  but  upon  w-ashing,  the  dye, 
while  permanent  in  silk  and  wool,  will  wash  out 
from  the  cotton  fabric.  Therefore,  some  sub- 
stances may  be  dyes  for  a  given  material,  but  not 
for  other  materials.  This  property  is  common  to 
many  dyes. 

Again,  materials  may  be  steeped  in  basic  dyes, 
like  rosanilin,  which  is  colorless  by  itself;  but  if  the 
material  has  previously  been  steeped  in  a  mordant, 
precipitation  of  a  colloidal  dye  with  the  mordant 
will  be  affected  in  the  fiber,  producing  lasting  fast 
(not  washed  out  or  bleached)  colors. 

Indigo,  on  the  other  hand,  is  converted  into 
leuco'indigotin  by  reducing  agents,  which  render 
it  soluble  in  water.  The  yarn  or  material  saturated 
with  this  solution  and  wrung  out,  iTpon  exposure, 
while  drying  will  become  dyed;  the  solution  is  con- 
verted to  the  insoluble  blue-indlgotin  deposited  in 
fibers  of  the  fabric. 

Various  decoctions  of  tanning  materials,  such  as 
nutgalls,  oak-bark  or  sumach,  upon  the  addition  of 
some  salt  of  iron,  produce  desirable  "ink-blacks" 
which  are  "fast." 


TRIATOMIC    PHENOLS.  47 1 

TRIATOMIC  PHENOLS. 

There  are  three  triatomic   (triacid)    i)hcnt)ls;  all 
isomeric  CbH3(OH)3  compounds: 

Of    these    three    isomers    pyrogallol    is    the    most 
important,  oxyhydroquinon  the  least. 

OH  OH  OH 


OH 


OH         OH  ' 


OH 


OH 


vicinal  trihydroxy-       symmetic  trihydroxy-  OH 

benzene  benzene  phloro-  -—. — — ^r: 

pyrogallol  glucinol  ^  "dro^^'-b^nzene^" 

oxyhydroquinone. 

PYROGALLOL,  C6H3(OH)3  (Scheele,  1786),  also 
called  pyrogaUic  acid,  like  all  phenols,  has  acid 
properties.     It  is  obtained  by  heating  gallic  acid: 

=z(ov[\  /'OH(i) 

C'R—^^^^f,  =  C«H3-OH(2)  +  CO,. 


2\C00H 


\0H(3) 


gallic  acid  pyrogallol. 

Pyrogallol  occurs  in  colorless  needles,  and  melts  at 
132°  C.  It  sublimes  readily  and  is  more  soluble  in 
water  than  in  alcohol  and  ether.  Pyrogallol  readily 
absorbs  oxygen,  and  for  that  purpose  is  employed  in 
gas  analysis.  It  is  a  prompt  reducing  agent,  em- 
ployed in  photography  and  as  external  antiseptic  in 
medicine.     Pyrogallol  is  very  poisonous. 

PHLOROGLUCINOL,  C6H3(OH)3,  phloroglucin, 
is  found  in  certain  resins  as  "dragon's  blood"  and 
gamboge.     It  can  be  prepared  by  fusing  resorcinol 


472  PHARMACEUTIC    CHEMISTRY. 

with  potash,  whereby  resorcinol  takes  up  another - 

oxygen  atom  from  the  air: 

/OH(i) 
CeH,(OH),  +  O  =  C„H.— OH(3) 
\0H(5) 

resorcinol  phloroglucinol. 

When  dissolved  in  strong  hydrochloric  acid,  it 
acquires  a  pink  color  in  the  presence  of  pentoses,  for 
which  it  is  a  reagent.  It  melts  at  218°  C,  sublimes 
readily  and  is  very  soluble. 

OXYHYDRCQUINON  is  oljtaincd  by  fusing  quinol 
with  caustic  soda. 

AROMATIC    ALCOHOLS,    ALDEHYDS    AND 
KETONES. 

The  aromatic  alcohols  possess  many  properties 
in  common  with  the  paraffinic  alcohols.  They  may 
likewise  be  produced  by  reactions  analogous  to  those 
discussed  under  the  Preparation  of  the  Aliphatic 
Alcohols: 

(i)  By  acting  with  moist  silver  oxid  on  a  halid  of  a 
benzene  homologue. 

(2)  By  reducing  an  aromatic  aldehyd  or  a  ketone. 

(3)  By  acting  on  amino  derivatives  of  the  aro- 
matic hydrocarbons  having  the  amino  group  in  the 
alkyl  (side  chain). 

The  two  following  are  tyi)ical  aromatic  alcoliols: 

BENZYL     ALCOHOL,    CeHj.CHjOM,     may     be 

prepared  by  any  of  the  above  reactions  or  by  boiling 

benzyl  chlorid  with  a  solution  of  potassium  carbonate : 

2C«H,CH,C1  +  K2CO3  +  H^O  =  2CeHs.CH,0H  + 

benzyl  chlorid  benzyl  alcohol 

2KCI    +   CO2 


PHENOL  ALCOHOLS. 


473 


Properties. — This  is  the  simplest  aromatic  alcohol ; 
it  occurs  naturally  in  the  balsams  of  tolu  and  Peru ; 
boiling-point,  206°.  It  forms  derivatives  and  substi- 
tution products  like  the  aliphatic  primary  alcohols; 
thus,  an  aldehyd — the  benzyl  aldehyd — and  an  acid 
— the  benzoic  acid: 

CH,OH  CHO  COOH 


benzaldehyd 

boiling-point, 

179°  C. 


benzoic  acid  melt- 
ing-point, 122°  C. 


benzyl  alcohol 

boiling-point, 

206°  C. 

CINNAMYL  ALCOHOL,  styrone,  CeHsCHiCH.- 
CH20H(C9HeOH). 

It  occurs  naturally  in  styrax;  it  is  a  crystalline 
body,  melting-point,  32°  C,  having  a  delightful 
hyacinth-like  odor.  It  is  obtained  by  reducing 
cinnamic  aldehyd  with  sodium  amalgam. 

There  is  another  class  of  aromatic  alcohols  and 
aldehyds  distinguished,  namely,  those  in  which  the 
hydroxy!  group  is  present,  both  in  the  side  chain 
and  the  nucleus;  or  the  OH  in  the  nucleus  and 
CH2OH  group  in  the  side  chain.  These  are  some- 
times called — 

PHENOL  ALCOHOLS.— Example,  ortho-hydroxy- 
henzyl  alcohol,  or  SALICYL  ALCOHOL,  saligenin, 
/OH 


CeH, 


XCH^— OH. 


Salicyl   alcohol   occurs   as   a   glucosid  in   certam 


474  PHARMACEUTIC   CHEMISTRY. 

willow  barks  under  the  name  sal  kin.  Salicin  acted 
upon  by  the  enzym  emulsin  yields  saUgenin.  It 
may  be  also  prepared  by  reducing  salicylic  aldehyd. 
It  is  a  water-soluble,  crystalline  substance,  melting 
at  82°  C. 

ANISYL  ALCOHOL,  para-methoxy-benzyl-alcohol, 
CeH,(OCH3)CH20H,  can  be  obtained  from  anisic 
aldehyd  by  treatment  with  alcoholic  potash.  Color- 
less crystals  melting  at  25°  and  boiling  at  259°; 
upon  oxidation,  converted  into  anisic  aldehyd,  and 
this  into  anisic  acid. 

VANIL-ALCOHOL,  vanillin  alcohol  CgHg.OH.- 
OCH3.CH2OH,  is  formed  from  vanillin.  Crystals 
melting  at  115°  C. 

PIPERONYL  ALCOHOL,  heliotropol,  is  formed 
from  piperonal  similarly  to  vanil-alcohol  by  reducing 
solutions  of  the  respective  aldehyds  with  sodium- 
amalgam.     Crystals  melting  at  57°  C. 

AROMATIC  ALDEHYDS.— These,  like  the  alco- 
hols, are  divided  into  those  containing  the  CHO 
(aldehydic)  group,  either  in  the  side  chain  or  in  the 
nucleus.  They  are  analogous  to  the  aliphatic  alde- 
hyds. Upon  oxidation,  they  yield  Aromatic  acids 
just  like  their  aliphatic  analogues.  The  general 
methods  of  preparation  of  the  aromatic  aldehyds  is  by: 

(i)  Oxidation  of  the  corresponding  alcohol  with 
nitric  acid  or  potassium  dichromate. 

(2)  By  distilling  a  mixture  of  the  corresponding 
acid  calcium  salt  with  calcium  formate. 

BENZALDEHYD,  CeHj— CHO  (benzaldehydum), 
is    artificially    produced    "oil    of    bitter    almc^nds." 


BENZALDEHYD-PREPARATION.  475 

It  may  also  be  obtained  from  natural  oil  of  bitter 
almonds,  peach-  or  cherry-kernel  oil,  etc.  The 
U.  S.  P.  requires  at  least  85%  of  benzaldehyd,  and  a 
boiling-point  of  180°,  specific  gravity,  1.045,  and  be 
free  from  hydrocyanic  acid  and  chlorinated  products. 

(i)  Benzaldehyd  may  be  obtained  by  macerating 
ground  bitter  almonds  when,  through  the  decom- 
position of  aniygdalin  in  the  presence  of  water, 
benzaldehyd  and  hydrocyanic  acid  are  formed: 

C.oH.7NOrT  +  (2)H,0  =  C6H,.CHO  +  HCN  +  :C6Hi,06 
amygaalii,  benzaldehyd  dextrose. 

(2)  By  the  interaction  and  distillation  of  calcium 
benzoate  and  formate: 

Ca(C6H5.COO).  +  Ca(H.COO).  =  2C6H,.CHO  +  2CaC03 
calc.  benzoate  calc.  formate  benzaldehyd. 

(3)  Commercially,  it  is  made  by  treating  toluene 
with  chlorin,  which  forms  henzal  chlorid,  CgHj.- 
CHCI2;  this  heated  under  pressure  with  slaked  lime 
gives  benzaldehyd: 

(a)  C6H,.CH3  +  2Cb  =  CeH.CHCl.  +  2HCI. 
toluene  benzal  chlorid 

(ft)  C6H5CHCI3  +  Ca(OH)=CaCb+C6H5CHO  +H,0. 

benzaldehyd. 

Description. — A  colorless  oil  with  a  strong  odor  of 
bitter  almonds,  but  free  from  hydrocyanic  acid, 
upon  oxidation  yielding  benzoic  acid,  which  is 
sometimes  seen  as  a  deposit  in  the  bottles  containing 
old  bitter  almond  oil.  It  is  not  poisonous  when  pure, 
but   its   freedom   from    hydrocyanic   acid   should    be 


476  PHARMACEUTIC   CHEMISTRY 

established.     With   nitric   acid   it  is  converted  into 
ortho-  and  metn-niti-obenzaldehyds. 

CI-I3         CH2OH       CHO       COOH    CHO 


toluene  boil-  benzylalcohol  benzaldehyd  benzoic  acid    o.  nitroben- 
ing-point,     boiling-point,  boiling-point,     melting-  zaldehyd, 

iii°C.  2o6°C.  i8o°C.       point,  i2i°C.       melting- 

point,  46°  C. 

To  the  class  of  phenol  aldehyds  or  oxyaldehyds 
the  following  belong: 

SALICYLIC  ALDEHYD,  saUcylal,  orchidee,  oil 
of  spirea  (meadow-sweet),  CgH^.OH.CHO,  can  be 
obtained  by  oxidizing  salicin  with  potassium  dichro- 
mate  in  presence  of  sulfuric  acid;  synthetically, 
it  is  made  by  heating  phenol,  chloroform  and  caustic 
potash.  Salicylic  aldehyd  has  an  adhesive  strong 
odor,  reminding  one  of  sweet  clover,  in  the  manufac- 
ture of  the  extract  of  which  it  enters;  it  has  the 
specific  gravity  of  1.17,  and  boils  at  196°  C. 
Reaction,  known  as  "Reimer's  synthesis": 
CeHj.OH  -f  CHCI3  +  3KOH  = 

^«"^\CHO  +  ^^^^  +  '"^^ 
CINNAMIC  ALDEHYD,  "synthetic  oil  of  cinna- 
mon" or  "cassia"  (cinnaldehydum),  CgH^.CH  = 
CH.CHO.  It  can  be  obtained  from  the  oils  of 
cinnamon  or  cassia  in  which  it  occurs  naturally, 
or  it  can  be  prepared  synthetically  by  condensing 
benzaldehyd  with  acetaldehyd,  evaporating  thejun- 
'Tombined    acetaldehyd   and    distilling    w^ith   steam 


VANILLIN.  47  7 

It  can  also — as  can  most  aromatic  aldehyds— be 
obtained  by  forming  a  bisulfitic  compound  with  the 
oil  of  cassia.  It  occurs  as  a  pale,  yellowish  liquid, 
having  a  strong  cinnamon-like  odor  and  taste,  boiling 
at  250°  C.  and  having  a  specific  gravity  of  1.047.  It 
should  be  at  least  95%  pure  and  free  from  chlorinated 
bodies. 

ANISIC    ALDEHYD,     CfiH,/"^^^'^^^  ,     anisal, 

"hawthorn  oil,"  aubepine,  can  be  synthetically 
obtained  by  oxidizing  fennel  or  anise  oil  with  nitric 
acid.  Chemically,  it  is  para-  methoxy  benzaldehyd,  a 
fragrant  oil,  boiling  at  246°  C,  and  having  a  specific 
gravity  of  1.126  (15°);  at  a  low  temperature,  solidi- 
fying. Upon  exposure  it  is  oxidized  to  anisic  acid. 
With  cumarin  and  orris  tincture,  in  alcoholic  solu- 
tions, it  constitutes  the  "new-mown  hay"  extract. 

PROTOCHATECHUIC  ALDEHYD,  C6H3(OH)2- 
CHO.  It  may  be  prepared  from  pyrocatechin  with 
chloroform  and  caustic  potash  (Reimer's  reaction). 
It  melts  at  150°  and  is  chiefly  of  interest  because 
of  its  close  relation  to  vanillin  and  heliotropin. 

VANILLIN,  tnethylprotocatechuic  aldehyd, 
/OCH3  (i) 
CeH3^0H      (2), 
\CHO   (4) 
occurs    naturally   in   vanilla   to    which    it    imparts 
its  delicious  odor  and  flavor.     It  can  be  prepared 
synthetically  by  "Reimer's  synthesis"  from  mono- 

methvl  ether  of  catechol  (CeH^^  „  _„      guaiacol). 
\ULxlo 


478  PHARMACEUTIC   CHEMISTRY. 

Of  late  it  has  been  prepared  by  oxidizing  eugenol 
(constituent  of  clove  oil)  with  ozone.  Vanillin  is  a 
delightfully  fragrant  substance,  with  an  odor  of 
vanilla,  melting  at  80°  C.  and  boiling  at  285°  C. 
When  2.5  %  of  vanillin  is  mixed  with  97.5%  of 
sugar,  "vanillin  sugar  "  is  produced  which  can  be  used, 
weight  for  weight,  in  place  of  the  best  vanilla  bean. 
CUMINIC  ALDEHYD,  CgHnCHO,  is  a  constituent 
in  the  volatile  oils  of  the  iimbellijercB  (cummin, 
caraway  and  water  hemlock). 

CHO(i) 

PIPERONAL,  CfiH^C^^CH,,    methylene    ether  oj 

0(4) 
protacatechuic  aldehyd,  hciiotropin,  may  be  ()l)tained 
])y  oxidizing  piperic  acid.  Small  fragrant  crystals, 
with  a  flowery  odor  of  bitter  almonds,  melting  at 
37°  C.  Recently  it  has  been  prepared  by  oxidizing 
isosafrol  with  pyrochromic  mixture  diluted  with 
water.  Heliotropin  possesses  a  delightful  clinging 
odor  of  the  white  heliotrope  flower,  and  mixed  with 
alcohol  its  2%  solution  with  cumarin  and  oil  of 
jasmin  forms  a  fragrant  "heliotrope  extract." 

AROMATIC  KETONES  are  analogous  with  the 
fattv  ketones;  their  general  formula  is  R  —  CO  —  R' 
— one  of  the  two  R  rei)rcsenting  an  aromatic 
radicle. 

ACETOPHENONE  is  a  typical  aromatic  ketone. 
Chemicall}-,  it  is  phciiyhiicthylkclone  or  acetyl 
benzene,    CgH.  —  CO  —  CH,.     It    is    produced    by 


THE    QUINONES. 


479 


distilling  a  mixture  of  calcium  benzoate  and  calcium 

acetate: 

Ca(C6H5.COO)3  +  Ca(CH3COO),  =  2C6Hs.CO.CH,  +  CaCO, 
acetophenone 

Acetophenone  crystallizes  in  large  transparent 
plates,  melting  at  21°  C,  and  boiling  at  200°  C,  and 
possessing  an  odor  like  benzaldehyd.  It  is  known 
in  pharmacy  as  hypnone,  and  in  medicine  employed 
as  a  soporific. 

BENZOPHENONE,  CeHs.CO.CeH^,  diphenyl 
ketone,  is  produced  by  the  dry  distillation  of  calcium 
benzoate: 

CaCQHs.COO),  =  CeH^CO-QHs  +  CaCOg. 

diphenyi  ketone. 

It  occurs  in  colorless  prisms,  melting  at  49°  C; 
on  reduction  with  sodium  amalgam,  it  produces  a 
corresponding  secondary  alcohol,  CgHj.CHOH.- 
^6^5  =  di phenyl  alcohol. 

THE  QUINONES  may  be  described  as  aromatic 
diketones.  Benzoquinon,  the  representative  of  the 
class  commonly  known  as  quinon,  is  usually  ob- 
tained hy  the  oxidation  of  para-derivatives,  such  as 
para-  amidophenol  or  hydroquinol: 
O 
OH  II 


+  0 


+  H,0 


OH 


hydroquinol 


480  PHARMACEUTIC    CHEMISTRY. 

TABLE  OF  AROMATIC    ACIDS   AND  HYDROXY 
ACIDS. 

Monobasic  Si:lurated  Acids. 

Melting- 
point 

Benzoic  acid,  C^Hg-COOH 121° 

Phenylacetic  acid.  C6H5.CH,.COOH 76° 

I  0-,  102° 
Toluic  acids,  CeH,(CH3).COOH -^  m-,  110° 

(  P-,  180° 
Hydrocinnamic  acid,  C6H5.CH2.CH2.COOH  .       4.9° 

Mesitylenic  acid   )  c^H3(CH3),COOH.  .  .  .  \     l^ 
Xylylic  acids         j     »    sv       3/2  /       ^  o 

Cumic  acid,  C6H,(C3H7)COOH ^     116-= 

Polyhasic  Saturated  Acids. 

COOH  )  i  0-,  213° 

Phthalic  acids,  CeH,/  -....-  m-,  300°  + 

^COOH  \  I        p- 

Trimesic  acid,  C8H3(COOH)3 300° 

Pyromellitic  acid,  C6H2(COOH), ^64° 

Benzene-penta-carboxylic acid,  CgH (COOH).      .... 
Mellitic  acid,  ^(COOH)^ .'      .... 

Unsaturated  Acids. 

Cinnamic  acid,  CeH5CH  =  CH.COOH 133° 

Atropic  acid,  CbHg.C^^p^^TT        106° 

Phenyl-propiolic  acid,  C6H5.C  =  C. COOH  .  .       136° 

Phenol  Acids  and  AlcoJiol  Acids. 

Salicylic  acid,  C6H,(OH)COOH 155° 

m-  and  p-  oxybenzoic  acids,  CbH^(OH)- 

COOH (  m-,  200^ 

(  P-,  210° 


AROMATIC  ACIDS.  481 

Anisic  acid,  C„H,(OCH3)COOH 184° 

Oxytolulic  acids,  CbH3(CH3)^  rOOH     i 

Melilotic  acid,  CoH,(OH)CHXHXOOH.  .  .      128° 
Mandelic  acid,  CeH^.CHOH.COOH 118° 

Tropic  acid.  C,Vi^Cll(^^f^^  }   117° 

Protocatechuic  acid,  CeH3(OH)2COOH 199° 

Vanillic  acid,  CeH3(OH)(OCH3).COOH..  .  .      207° 
Orsellinic  acid,  QH^fCHg)  (OI-I),COOH. ...       176° 

Gallic  acid,  C6H2(OH)3.COOI-I.'' 222° 

Tannic  acid,  Cj^H^pOg 

Quinic  acid,  C,H.Hg(OH),COOH 162° 

Unsaturated  Phenol  Acid. 

Coumaric    acid,    C6H,(0H)CTI  =  CH.- 

COOH (  0-,  208° 

I  P-,  206° 

AROMATIC  ACIDS. 

These  acids  are  also  known  as  carboxylic,  andean 
be  produced  by  methods  analogous  to  those  em- 
ployed in  the  production  of  the  aliphatic  acids. 
These  acids  are  divisible  into  three  classes:  Those 
containing  the  carboxyl  group  in  the  side  chain,  as 
cinnamic  acid,  CgHg.CH  =  CH.COOH;  those  con- 
taining the  carboxyl  group  on  the  nucleus,  as  benzoic 
acid,  CeHg.OH,  and  those  which  besides  the  carboxyl 
group  contain  also  a  hydroxyl  group.  This  third 
class  of  acids  is  known  as  "phenol-  or  alcohol- 
acids'';  example,  salicylic  acid,  CyHj.OH.COOH. 


482  rHARMACEUTIC   CHEMISTRY. 

CH=CH.COOH         COOH  COOH 

'\  /\  /\  OH 


cinnamic  acid  benzoic  acid  salicylic  acid 

(hydroxy-benzoic) 

General  Properties.— AW  the  aromatic  acids  are 
crystalline;  all  sparingly  soluble  in  water,  but  freely 
in  the  organic  solvents.  They  can  be  distilled  with- 
out decomposition,  but  when  distilled  with  lime  they 
are  decomposed,  losing  carbon  dioxid  and  forming 
a  corresponding  hydrocarbon: 

C.Hs.COOH  +  CaO  =  ^CeHe..  +  CaCOg. 

benzoic  acid  benzene. 

BENZOIC  ACID,  CfiH.COOH,  was  so  named 
because  it  was  first  obtained  from  the  balsamic 
resin — benzoin. 

Like  all  the  organic  acids,  it  can  be  produced  by 
one  of  the  following  general  methods: 

(i)  By  the  oxidation  of  the  corresponding  aro- 
matic alcohols  and  aldehyds. 

(2)  By  hydrolysis  of  a  corresponding  nitril. 

(3)  By  the  oxidation  of  the  side  chain  of  a  cyclic 
hydrocarbon  containing  such. 

The    general    reactions    may    be    exemplified    by 
equations  showing  the  production  of  benzoic  acid" 
(i)  CeHs.CH^OH  -I-  2O,  =  CgHs-COOH  -|-  H,0. 

benzvl  alcohol  benzoic  acid 

(2)  CeH,.CIK)  +  O  =  CoH,.COOH. 

benzaldchyd 

(2)  C«H,.CN  +  2H.,()  -  C^Hj.COOH  +  NH.,. 


DERI\ATIVF,S    OF    BENZOIC    ACID.  483 

The  most  common  method  of  producing  benzoic 
acid  is  the  third  one — oxidizing  a  side  chain  of  a 
hydrocarbon;  thus,  by  the  oxidation  of  toluene  by 
dilute  nitric  acid: 

CeHs.CH3  +  30=  CeH^COOH  +  H.O. 

toluene. 

Properties  oj  Benzoic  Acid. — Glistening  colorless 
needles,  melting  at  121°  C.  and  boiling  at  250°; 
sparingly  soluble  in  water,  freely  in  the  organic 
solvents. 

Benzoic  acid  is  also  produced  from  "hippuric 
acid"  as  well  as  toluene;  but  in  pharmacy  for 
internal  use,  o«/y  that  suhlirned  jrom  benzoin  should 
he  employed: 

Benzoic  acid  is  used  as  a  preservative  in  foods, 
but  its  use  should  be  prohibited,  in  that  it  is  converted 
into  phenol  by  the  liver  and  acts  as  a  cumulative 
systemic  poison. 

Tests. — (i)  Aqueous  solutions  of  benzoic  acid 
and  its  soluble  salts  give  with  ferric  chlorid  salmon- 
colored  precipitates. 

(2)  A  benzoate  dissolved  in  alcohol  to  which  a 
few  drops  of  H2S0^  have  been  added,  upon  heating, 
yields  the  characteristic  odor  of  ethyl  benzoate. 

(3)  Silver  nitrate  added  to  a  solution  of  a  benzoate 
is  precipitated  as  a  crystalline  silver  benzoate  which, 
on  ignition,  yields  a  residue  of  47.1^;,'  of  silver. 

DERIVATIVES  OF  BENZOIC  ACID. 

THE  ESTERS.— These  can  be  prepared  b.\- 
methods  analogous  to  the  paraffinic  esters. 

METHYL    BENZOATE,     CeH^.COOCHg,     is    a 


484  PHARMACEUTIC    CHEMISTRY. 

colorless  oil,  boiling  at  199°  C.  and  having  a  fra- 
grant odor.     Synonym,  "niobe  oil." 

ETHYL  BENZOATE,  CeHs.COOQH,,  a  fragrant 
licjuid,  boiling  at  212°  C. 

BENZYL  BENZOATE,  CoH^.COO.CeHs,  is  found 
naturally  in  cinnamein  (oil  of  balsam  peru);  may  be 
obtained  from  l)enzyl  chlorid  and  benzyl  alcohol. 

BENZOYL  CHLORID,  C,.H5.CO.Cl,  is  obtained 
by  treating  benzoic  acid  with  phosphorus  j)enta- 
chlorid.  It  bears  the  same  relation  to  benzoic  acid 
that  acetyl  chlorid  does  to  acetic  acid  and,  like  the 
latter,  it  is  an  important  reagent  in  organic  synthesis. 

It  is  a  colorless  oil  with  a  very  irritating  odor,  and 
boils  at  198°  C.  With  water  it  is  gradually  decom- 
posed into  benzoic  and  hydrochloric  acids. 

BENZOIC  ANHYDRID  is  produced  when  IjcnzoyI 
chlorid  is  treated  with  .sodium  benzoate.  It  is  a 
crystalline  substance,  melting  at  42°  C,  and  has  the 
formula  (CeH5.CO)20.  The  monovalent  benzoyl 
group  has  the  formula  C„H..CO. 

BENZAMID,  C„H5.CO.NH„  is  a  typical  example 

of  an  aromatic  amid.     It  can  be  produced  in  much 

the  same  way  as  acetamid  of  the  fatty  compounds: 

CeH,  COOC.H^  +  NH3  =  C6H,.CO.NH,  +  C^Hj.OH. 
ethyl  benzoate  benzamid. 

Eenzamid  occurs  in  sparingly  soluble  crystals, 
melting  at  130°  C.  When  heated  with  alkalis 
it  is  decom})osed,  yielding  ammonia  and  a  corre- 
sponding salt: 

CcIIs.CO.NH,  +  KOH  =  CeH.COOK  -I-  NH3. 


HALOGEN    DERIVATIVES    OF    BENZOIC    ACID.    485 

BENZONITRIL  or  phenyl  cyanid,  CeHj.CN,  can 
be  prepared  by  treating  benzamid  with  dehydrating 
agents: 

CeHj.CO.NH^   =   C6H5.CN    +   H^O. 

benzo  nitril. 

It  may  also  be  prepared  from  an  anilin  derivative — 
diazobenzene  chlorid — by  treating  it  with  cuprous 
cyanid  {Sandmeyer^s  reaction): 

C6H5.N2CI   +  CuCN   =  C6H5.CN   +  CuCl   +  N2. 

benzo  nitril. 

Benzonitril  has  the  odor  and  appearance  of  nitro- 
benzene, but  it  boils  at  191°  C. 

HALOGEN  DERIVATIVES  OF  BENZOIC  ACID.— 
Benzoic  acid  is  attacked  by  the  halogens,  although 
not  so  readily  as  the  hydrocarbons.  The  following 
are  the  more  important  products: 

META-BROMBENZOIC  ACID,  C6H,.Br.C00H, 
melting  at  155°  C. 

ORTHO-BROMBENZOIC  ACID,  C\H,.Br.COOH, 
melting  at  147°  C. 

PARA-BROMBENZOIC  ACID,  CeH,.Br.COOH, 
melting  at  251°  C. 

All  the  above  acids  last  mentioned  are  made  by 
oxidizing  corresponding  bromtoluenes  with  nitric 
acid. 

When  nitric  acid,  in  presence  of  sulfuric  acid,  acts 
on  benzoic  acid,  the  following  nitro  derivatives  are 
obtained: 

ORTHO-NITROBENZOIC  ACID,  CeH^.NOj.- 
COOH;  melts  at  147°  C. 

META-NITROBENZOICACID.CeHj.NOa.COOH; 
melts  at  141°  C. 


486  PHARMACEUTIC   CHEMISTRY. 

PARA-NITROBENZOIC  ACID,  C.H^.NOjCOOH; 

melts  at  238°  C. 

ANTHRANILIC  ACID  is  orthcj  amidobenzDic  acid, 
^„/COOH(i) 
^«"^\NH2      (2). 

It  is  produced  by  boiling  indigo  with  caustic  alkali. 

When  heated  with  sulfuric  acid,  benzoic  acid  is 
converted  into  mono-sulfol)enzoic  acid, 

Ortho-sulfobenzoic  acid  is  obtained  by  o.xidizing 
toluene  ortho-sulfonic  acid.  This  acid  treated  with 
ammonia  yields  suljo-henzo-imid,  commonly  known 
as  "saccharin,^'  ghicin,  guraniose,  etc.: 

/SO^OHCi)    ,   NH  = 
^«"%CQ0H(4)  ^  ^^"^^ 

ortho-sulfobenzoic  acid 

^«"^\CO/^"  +  2H,0. 

saccharin 

SACCHARIN  (benzosulphinidum),  benzosidfinid, 
is  about  450  times  as  sweet  as  sugar,  and  one  gram 
of  it  will  afford  the  sweetening  ecjuivalent  to  i 
pound  of  granulated  sugar.  It  is.  used  for  this 
purpose  and  in  this  proportion  to  sweeten  the  jood 
oj  diabetic  patients.  Its  use  as  a  sweetener  of  ordi- 
nary foods  should  be  prohibited,  as  its  use  is  produc- 
tive of  bad  effects  on  the  plasma  of  the  blood. 

There  are  three  isomeric  toluic  acids  (o.  m.  p.), 
which  may  be  produced  by  o.xidizing  the  corre- 
sponding three  xylenes  with  nitric  acid;  thus: 

r  TT  /C^^.i(^^    -4-  ^O  ^  r  H  ^^^3        4-H  O 


TOLUIC   AND    PHTHALIC   ACIDS.  487 

ORTHO-TOLUICACID.CgH./^^Qj^j^  ,  melts  at 
103°  C. 

META-TOLUIC  ACID,  C^H, .  ^Jj^^j^  ,  melts  at 
110°  C. 

PARA-TOLUIC   ACID,    CgH^C^^^^^jj  ,  melts  at 

180°  C. 

All  the  toluic  acids  are  crystalline  and  all  resemble 
benzoic  acids,  and  each,  like  benzoic  acid,  furnishes 
a  corresponding  chlorid,  amid,  anilid,  nitro  acid,  etc., 
by  the  usual  methods. 

The  three  phthalic  acids  analogous  to  the  fore- 
going have  the  graphic  formulas: 

COOH       COOH       COOH 
^  COOH   r'  ' 
I    ■     I 


COOH 


COOH 


phthalic  acid  melt-  iso-phthalic  acid  terephthalic   acid 

ing-point,  213°  C.  melting-point,  (sublimes  without 

300°  C.  melting) 

The  PHTHALIC  ACIDS  above  can  be  obtained 
by  treating  corresponding  toluic  acids  with  potassium 
permanganate  in  alkalin  solution: 

r  H  -^^^3      4-  oo  —  r  H  ^  COOH    TT  Q 

^«"*\COOH  +  3^  -  '-e^ix  COOH  +^2'-'- 

When  strongly  heated,  phthalic  acid  yields: 

PHTHALIC  ANHYDRID,  CgH^C^^Q^O,  melting 
at  128°  and  boiling  at  284°.     PhthaUmid  is  obtained 


488  PHARMACEUTIC    CHEMISTRY. 

from  the  anhydrid  by  heating  it  with  ammonia.  It 
melts  at  229°  C. 

CUMIC  ACID,  para-isoi)ropylbenzoic  acid,  C3H7.- 
Cgll^-COOH,  is  oljtained  Ijy  the  oxidation  of  cuminol. 

UNSATURATED  AROMATIC  ACirS.  The  fol- 
lowing are  representatives: 

Phenylacetic   acid,    CoHs.CHjCOOIT,    melting   at 

76.5°- 

Phenyl    propionic    acid,    CeH5.CH.,.CH2.COOH, 

melting  at  47°. 

Cinnamic  acid,  C«H,.CH:CHCOOH,  also  called 
phenylacryUic  acid  belongs  to  the  class  of  unsaturated 
aromatic  acids.  It  occurs  naturally  in  the  balsamic 
resins — tolu,  peru  and  styrax — and  may  be  syn- 
thetically prepared  by  '' Perkins'  reaction.'''  This 
last  is  also  a  general  method  for  the  preparation  of 
the  unsaturated  aromatic  acids,  and  depends  upon 
the  heating  of  an  aldehyd  (either  aliphatic  or 
aromatic,  depending  upon  the  product  desired) 
with  the  sodium  salt  of  a  fatty  acid  and  its  or  some 
other  anhydrid.  The  heating  at  180°  is  continued 
for  several  hours.  Condensation  occurs,  splitting  off 
water,  which  is  absorbed  by  the  anhydrid.  The 
anhydrid  is  thus  converted  into  an  acid  which  liber- 
ates the  corresponding  acid  from  its  sodium  salt. 

Cinnamic  acid  is  produced  by  the  above  reaction 
from  a  mi.xture  of  benzaldehyd,  acetic  anhydrid  and 
anhydrous  sodium  acetate,  which  is  heated  to  180°. 

(i)  C6II5.CHO+  CH3CO.ONa  =  C6li5CII.CII.,.CO.ONa 

OH. 

sodium  phenyl-lactate 


THE    HYDROXY   ACIDS. 


489 


C«H, 


which  occurs  naturally  in  oil  of 


(2)  C6H5.CH.CH.CO.ONa  +  (CH3C0).0  = 

[         I  acetic  anhydrid 

OHH 

(3)  C6H,.CH:CH.COOH  +  CH3CO.ONa  +  CH3COOH. 

cinnamic  acid. 

Cinnamic  acid  is  readily  soluble  in  hot  water;  it 
melts  at  133°  C.  and  sublimes  at  300°  C. 

THE  HYDROXY  ACIDS  include  the  important— 
SALICYLIC  ACID,  ortho-hydroxy  benzoic  acid, 
'OH  (2) 
XOOH(i)' 

wintergreen  (gaultheria)  as  a  methyl  ester  (methyl 
salicylate).  It  can  be  obtained  (i)  by  fusing 
salicin  with  caustic  soda;  (2)  by  boiling  oil  of  winter- 
green  with  potassium  hydroxid  solution,  whereby 
potassium  salicylate  is  formed.  Methyl  alcohol 
being  liberat.^d. 

/COOK 
^\OH 

(3)  by  heating  phenol  with  caustic  soda  in  a  cur- 
rent of  carbon  dioxid — "  Kolbe's  synthesis  ". 
QH^.O.Na  +  CO.  =  C.H^O.CO.ONa 

sodium  phenolate 

When  this  is  heated  to  1 
forms: 

O.CO.ONa 

H 


CeH,^^g^^"-HKOH: 


C«H 


+  CH3OH. 


.sodium  phenyl  car- 
bonate. 


C,  sodium  salicylate 


OH 


CO.ONa 


sodium   phenyl 
carbonate 


sodium  salicylate. 


490  PHARMACEUTIC    CHEMISTRY.. 

Thus,  the  high  heat  effects  the  intramolecular 
change.  Sodium  salicylate  is  decomposed  with 
sulfuric  acid,  and  salicylic  acid  is  set  free. 

Properties. — Salicylic  acid  occurs  in  fine,  white, 
sparingly  soluble  crystals  melting  at  155°  C.  and 
readily  soluble  in  the  organic  solvents.  It  is  a 
valuable  external  antiseptic  and  a  preservative,  but 
unsuiied  for  internal  administration.  For  this  later 
purpose  only  its  sodium  salt,  which  has  been  pre- 
pared from  the  oil  of  wintergreen,  should  be  em- 
ployed.    The  same  may  be  said  of  all  its  other  salts. 

Tests. — With  ferric  chlorid  soluble  salicylates  give 
a  violet-red  color  (distinguished  i  in  500,000  parts). 

SALOL     is     the     phenylester     of     salicylic    acid, 

CgH^./  p...,  TT  ?   phenyl   salicylate;  it   is  obtained 

when  salicvlic  acid  is  heated  alone  to  210°  C: 
'  /OH        _p„/OH 
•\COOH~'^«"^\COO.C6H5 
H2O;  also— 

(2)  By  heating  phenol  with  salicylic  acid  in  the 
presence  of  phosphorus  oxychlorid: 

3CeH,(^^^^^^  +  .sCeH^OH  +  f  OCI3  = 

phenyl  salicylate. 

Properties. — A  white,  crystalline,  tasteless  powder, 
converted  in  the  body  to  phenol  and  salicylic  acid 
by  the  pancreatic  juice  (it  is  insoluble  in  the  peptic 
juices),  and  excreted  by  the  urine  as  such.  It 
possesses  an  aromatic  odor,   is  insoluble    in   water 


SALOPHEN,    SALIPYRIN,    ORTHOFORM.  491 

and  melts  at  43°  C.  Owing  to  its  low  melting- 
point  and  insolubility  in  the  stomach,  it  is  used  for 
the  coating  of  enteric  pills. 

COOCH3 
SANOFORM,  CgHj— OH  ,  is  di-iodo-salicylic 

methylester,  prepared  by  acting  on  the  oil  of  winter- 
green  with  iodin.  Insoluble  in  water,  soluble  in 
alcohol;  it  melts  at  100°  C. 

SALOPHEN,  acetyl  par a-amido phenyl  salicylate, 
C6H,(OH)COO.C6H,NH.COCH3,  a  substitute  for 
salol,  it  splits  in  the  intestines  into  acetyl  para- 
amido-phenol  and  salicylic  acid.  It  melts  at 
187°  C. 

SALIPYRIN  is  obtained  by  heating  together  57.7 
parts  of  antipyrin  with  42.3  parts  of  salicylic  acid, 
cooling  and  crystallizing  from  hot  alcohol.  Spar- 
ingly soluble,  it  melts  at  92°  C. 

NIRVANIN,  a  hydrochlorid  of  diethyl-glycocoll- 
amido-oxybenzoic  methyl  ester.  It  is  used  for  pro- 
ducing local  anesthesia  as  a  substitute  for  cocain 
which  is  more  toxic,  also  used  in  dental  practice 
in  2  to  5%  solutions.     It  has  the  formula 

/NH.OCCH,N(CH5)2(s) 
C6H3— 0H(2) 

■\COOCH3(i) 

ORTHOFORM  is  related  to  nirvanin  in  properties, 
but  is  more  toxic.     It  is  the  methylester  of  amido- 

/NH^Ci) 
hydroxy  benzoic  acid  =  CgHa— 0H(2) 

\C00CH3(4). 


492  PHARMACEUTIC   CHEMISTRY. 

ASPIRIN  is  acetyl  salkylk  acid,  C^^/^QQ^^f 
BETOL    is    the    naphlliol   ester    oj   salicxlic   acid, 
C  H  /^^" 

METHYL   SALICYLATE,    ^\^4(^(jq  q^     -  i^ 

the  proximate  principle  found  in  the  oil  of  gaultheria 
(wintergreen)  and  oil  of  betula.  It  can  be  obtained 
synthetically  by  distilling  a  mixture  of  salicylic  acid, 
methyl  alcohol  and  sulfuric  acid.  For  flavoring 
purposes  methyl  salicylate  (methylis  salicylas),  oil 
of  gaultheria  and  the  oil  of  betula  may  be  said  to 
be  identical;  for  internal  administration,  however, 
only  the  last  two  should  be  used. 

Among  the  dihydroxy  (dioxy)  benzoic  acids,  the 
■following  may  be  mentioned. 

PROTOCATECHUIC  ACID,  C6H3(OH)2.COOH4- 

H2O,  is  one  of  six  isomeric  dihydroxy  benzoic  acids. 

It  is  found  in  many  of  the  commoner  resins,  coloring 

matters,  also  in  many  tannins.     It  has  the  structure: 

COOH 


HO 


HO 


proto-catechuic  acid,  melt- 
ing-point, 199°  C. 


■   COUMARIN  is  the  ivfier  ester  (lactone)  of  ortho- 

CU:  Cli 
livdroxv,  cinnamic  acid,  C,iHj:'  1  ;    it    oc- 

\o— c  =  o 


TRIHYDROXYBENZOIC   ACIDS.  493 

curs  in  very  white  crystals,  possessing  a  very  fragrant 
odor  of  woodruff,  tonka  bean  and  new-mown  hay, 
of  which  it  is  a  constituent.  It  is  prepared  from 
salicylaldehyd  by  the  Perkins  reaction,  and  is  much 
used  in  perfumery  and  soaps;  it  blends  well  with 
aubepine  and  heliotropin,  and  melts  at  67°. 

TRIHYDROXYBENZOIC  ACIDS.— Among  these 
but  two,  gallic  and  ellagic  acids,  are  of  importance. 

GALLIC  ACID,  C6H2(OH)3COOH.  It  is  pre- 
pared by  exposing  moistened  nutgalls  to  the  air, 
when,  by  influence  of  a  certain  peculiar  fermenta- 
tion, tannin  is  converted  into  gallic  acid.  It  can 
be  prepared  from  gallotannic  acid,  of  which  it  is  an 
anhydrid,  by  boiling  it  with  dilute  acids.  It  can  be 
separated  from  gallotannic  acid  because  it  is  soluble 
in  aqueous  ether. 

Gallic  acid  occurs  in  colorless  crystals,  melting 
at  220°  C,  readily  soluble  in  hot  water,  less  so  in 
cold  water. 

Tests. — (i)  With  ferric  chlorid  a  deep  blue  ink 
is  produced. 

(2)  With  potassium  cyanid  a  pink  precipitate  is 
produced,  which  fades  on  standing,  but  reappears 
on  shaking. 

(3)  It  does  not  precipitate  gelatin  (distinction 
frpm  the  tannins). 

ELLAGIC  ACID  is  a  yellow,  crystalline,  insoluble 
substance,  closely  related  to  gallic  acid  and  found 
together  with  certain  tannins,  as  in  sumac,  etc. 

DERMATOL  is  the  basic  bismuth  gallate,  Bi(  OH),- 
C«H2(OH)3C02;  a  yellow,  insoluble  powder. 


494  PHARMACEUTIC    CHEMISTRY. 

AIROL  is  the  oxyiodid  of  basic  bismuth  gallate, 
CgH2(OH)3Bi  (^  ;  a  greenish,  voluminous,  insol- 
uble powder. 

THE  TANNINS. 

This  name,  as  well  as  that  of  "tannic  acids,"  is 
applied  to  a  large  number  of  substances  which 
have  the  property  of  forming  insoluble  compounds 
with  the  albumin  of  the  raw  hides  by  which  they 
are  absorbed. 

The  ordinary  "tannic  acid"  is  the  monobasic 
gallotannic  acid,  obtained  from  nutgalls  (which 
contain  50%  of  tannin);  chemically,  it  is  digallic 
acid;  i.  e.,  a,  condensation  product  of  two  molecules 
of  gallic  acid  with  the  elimination  of  one  molecule 
of  water.  And  in  reality,  upon  heating  tannic  acid, 
gallic  acid  is  produced: 

Q,H,oO,  +  H,0  =  2C,H,0,. 

tannic  acid  gallic  acid. 

TANNIC  ACID  (acidum  tannicum),  HC,^H,o09, 
gallotannic  acid,  or  digallic  acid.  Prepared  from 
nutgall  by  maceration  with  water  and  e.xtraction 
with  ether.  When  heated  in  presence  of  moisture 
by  chemical  reaction  it  is  converted  into  gallic  acid. 
Light  yellowish,  amorphous  powder;  strongly  astrin- 
gent taste;  soluble  in  0.34  part  water  and  in  0.23 
part  alcohol,  in  i  part  glycerin  with  heat,  freely  in 
dilute  alcohol;  insohible  in  ollur  soheiits;  with 
ferric  chlorid  it  produces  bluish-black  color  which 
upon  addition  of  lime-water  is  converted  into  bluish- 


495 


white  and,  with  excess  of  lime-water,  pinkish.  It 
precipitates  gelatin,  alkaloids  and  metallic  salts,  and 
with  potassium  chlorate  and  other  strongly  oxidizing 
agents,  it  is  explosive.  When  in  solution,  it  forms 
ink  with  iron  salts,  and  its  preparations  should  not 
be  brought  in  contact  with  iron  vessels  or  spatulas. 
(Preparations:  CoUodium  stypticum,  glyceritum, 
troche,  unguentum.) 

OH  OH  OH 

Structure:  ^^   OH         HO  ^^         ^^   OH 


OH 
COOH 


HO 


OH 


CO— O— CO 


gallic  acid  tannic  acid  (digallic  acid). 

In  the  arts  it  is  used  as  a  mordant  for  certain  dye- 
stuffs,  and  in  the  manufacture  of  inks;  but  for  the 
tanning  of  leather  cheaper  varieties  of  tannin  are 
employed. 


OTHER  TANNINS. 

Tannin  is  a  substance  peculiar  to  the  vegetable 
kingdom  and  widely  distributed.  Various  modi- 
fications of  it  are  known.  Thus  in  nutgall,  as 
gallotannic  acid,  in  oak  as  quercitannic  acid,  and  in 
catechu,  krameria  and  cinchona  as  catechu,  kramero- 
tannic  and  cinchotannic  acid,  respectively.  They 
are  composed  of  C,  H  and  O  in  varying  propor- 
tions. Tannins  are  usually  amorphous;  soluble 
in  water,  alcohol  and  glycerin.     Their  solutions  are 

,12 


496  PHARMACEUTIC   CHEMISTRY. 

acid  in  reaction  and  precipitated  by  most  of  the 
metallic  salts  and  the  alkaloids.  When  boiled  with 
dilute  acids  they  split  into  glucose  and  phlobaphene, 
being  therefore  regarded  as  glucosids,  their  chief 
property  being  that  they  form  insoluble  compounds 
with  gelatin  and,  therefore,  are  used  in  tanning  of 
leather.  They  are  astringent  when  applied  to 
mucous  membranes,  and  upon  this  depends  their 
therapeutic  value.  With  iron  salts  the  tannins 
produce  characteristic  colorations  from  green  to 
blue-black,  the  different  shades  allowing  of  their 
being  identified  and  distinguished. 

Other  important  sources  of  tannin  are  among  the 
following: 

SUMACH,  leaves  of,  Rhus  coriaria  and  Rhus 
glabra. 

OAK,  l)ark  of,  Quercus  alba. 

MYROBALANS,  fruit  of  Tcrmuuilia  chchiilo. 

CUTCH,  extract  of  the  wood  of  Acacia  catechu. 

HEMLOCK,  bark  of  Abies  canadensis. 

POMEGRANATE,  bark  of  Piinica  granatum. 

CHESTNUT,  Iwrk  of  Castanea  vesca. 

TANNING  is  the  process  of  treating  hides  uifh 
tannin,  to  prevent  putrejactive  changes  and  to  render 
the  so-produced  leather  permanently  flexible. 

Tanning  is  effected  by  first  soaking  the  raw  hides 
in  milk  of  lime  to  remove  the  hair  and  at  the  same 
time  to  swell  the  skin.  The  lime  is  ne.xt  dissolved  out 
by  soaking  the  skins  in  "old  tan  liquor"  (containing 
lactic  and  citric  acids — produced  by  fermentation) 
or  in  fermenting  dung.     The  skins  are  then  digested 


THE    GLUCOSIDS.  497 

(steeped)  in  "tan  liquor" — an  aqueous  extract  oj 
tannin,  which  precipitates  the  albumin  of  the  skin, 
which  is  absorbed  by  the  skin,  rendering  it  insoluble 
flexible  and    porous — or  leather. 

During  the  past  few  years  the  tanning  of  leather 
has  been  effected  by  other  substances;  thus,  chrome 
alum  has  made  the  "chrome-tanned"  American 
leather  famous  for  its  good  wearing  and  elastic 
equalities.  Other  chromates  and  formaldehyd  have 
also  been  successfully  used. 

THE  GLUCOSIDS. 

The  term  "glucosid"  or  "glycosid"  is  applied 
to  a  class  of  proximate  principles  which  may  be 
regarded  as  ethers  chemically. 

The  term  glucosid  was  applied  to  these,  owing  to 
the  fact  that  they  are  readily  hydrolized  into  "glu- 
cose" when  warmed  with  dilute  acid  or  alkalin 
liquids,  and  in  this  respect  they  differ  from  the  true 
ethers;  also,  by  the  enzym.es:  if  one  of  these  is  of 
albuminous  nature,  glucose  is  formed. 

The  foregoing  class  of  tannins  are  frequently 
classed  with  the  glucosids. 

For  convenience  we  will  discuss  the  neutral 
principles  under  this  head. 

The  neutral  principles  include:  aloin,  chrysarobin, 
emodin,  elaterin,  santonin,  picrotoxin,  podophylo- 
toxin. 

The  glucosids  include:  arbutin,  salicin,  strophan- 
thin,  quercitrin,  amygdalin,  sinigrin  and  the  glucosids 
of  d  gitalis. 


498  PHARMACEUTIC   CHEMISTRY. 

They  all  contain  C,  H  and  ().  While  some 
contain  also  N  in  addition,  and  others  S.  Thus, 
amygdalin,  CjoHjyNOn,  is  nitrogenized,  while 
sinalbin,  CjoH^jNzSjOig,  and  sinigrin,  C,oHjpNS^,- 
KO9  +  H2O  are  sulfurated  glucosids.  They  are 
nearly  all  insoluble  in  water,  though  readily  soluble 
in  alcohol.  Their  English  names  end  in  "in,"  the 
Latin  in  "iniiui."  To  distinguish'  them  jrom  alka- 
loids ending  in  "ine,"  Latin  "ina." 

The  neutral  principles  are  solid,  crystalline  sub- 
stances derived  from  plants.  They  are  composed 
of  C,  H  and  O;  insoluble  in  water,  freely  soluble 
in  alcohol,  sparingly  in  ether  and  chloroform. 
They  differ  from  the  glucosids  in  not  being  split  into 
glucose,  and  from  alkaloids  in  that  they  are  not 
precipitated  by  tannin  and  other  alkaloidal  reagents. 
Sometimes  they  are  classed  as  ''bitter  jirinciples," 
on  account  of  their  taste. 

ALOIN  (aloinum)  Cj^HigO^,  obtained  from  several 
varieties  of  aloes,  chiefly  Curacoa  aloes.  Prepared 
by -extracting  aloes  with  acidulated  boiling  water, 
concentrating  and  crystallizing  from  warm,  dilute 
alcohol.  A  crystalline  powder  of  yellowish  color; 
soluble  in  65  jjarts  water,  10  parts  alcohol.  Used  in 
pills  as  a  cathartic.  Dose,  0.06.  Preparation:  Pil. 
laxat.  comp. 

ELATERIN  {elaterinum),  C^o^^js^^^v  Obtained 
from  elaterium,  which  is  deposited  in  the  juice  of 
the  fruit  of  ecbalium  elaterium.  Minute  white 
crystals,  sparingly  soluble  in  the  solvents,  except 
in  22  parts  chloroform.     Used  in  the  official   lo'/J 


NEUTRAL    PRINCIPLES.  499 

trituration  as  hydrogogue  cathartic.  The  Clutter- 
bucks  elaterin  is  the  most  reliable.     Dose,  0.03. 

PICROTOXIN  {picrotoxinum)  is  soluble  in  240 
parts  water  and  9  parts  alcohol.  Used  in  o.ooi  gm. 
doses. 

SALICIN  {salicinum),  QgHjgOy,  a  glucosid  ob- 
tained from  several  species  of  the  salix  and  populus 
by  digestion  with  lead  oxid,  extraction  with  water, 
purification  with  charcoal  and  crystallization.  Silky 
needles,  soluble  in  21  parts  water,  71  parts  alcohol, 
insoluble  in  other  solvents.  Colored  violet  with 
ferric  chlorid;  sulphuric  acid  dissolves  it  with  red 
color.  Saliva  resolves  it  into  saligenin  and  glucose. 
Used  in  rheumatism. 

CuHigO^  -f  H2O  =  C.Hi.Og  +  CbH,.OH.CH,OH. 

saligenin 

SANTONIN  {santoninum) ,  CisHj^O,,  the  inner 
anhydrid  or  lactone  of  santonic  acid.  Obtained 
from  santonica  by  boiling  levant  worm-seed  with 
calcium  hydroxid,  decomposing  this  salt  with  HCl, 
dissolving  in  hot  alcohol,  purifying  with  charcoal 
and  crystallizing.  Flat,  prismatic  crystals;  soluble 
in  35  parts  alcohol,  78  parts  ether,  2.5  parts  chloro- 
form. Turns  yellow  when  exposed  to  light.  Used 
in  the  official  troche,  containing  0.03  gm.  in  each, 
as  a  worm  remedy. 

CHRYSAROBIN  (chrysarobinum),  a  neutral  prin- 
ciple extracted  from  goa  powder.  A  pale,  orange- 
yellow  powder,  darkens  on  exposure,  soluble  in  150 
parts  boiling  alcohol,  insoluble  in  water.  Used  in 
ringworm  and  other  skin  diseases.     Dose,  0.03  gm. 


500  PHARMACEUTIC    CHEMISTRY. 

With  oxidizing  agents  it  is  oxidized  to  chrysophanic 
acid.     Prei)araliun:     Unguentum  6%. 

STROPHANTHIN  (strophanihinum),  €,^^^^0^^,  a 
glucosid  or  mixture  of  glucosids  ol^taincd  from  stro- 
phanthus.  Yellowish-white,  crystalline  powder,  in- 
tensely bitter,  very  soluble  in  water  and  dilute  alco- 
hol, insoluble  in  other  solvents.  Used  to  regulate 
heart  action.     Dose,  0.0003  K^-  (t^u  grain). 

Glucosids  obtained  jrom  Digitalis  purpurea: 

DIGITOXIN,  CjsH^bOio,  most  active  glucosid  of 
digitalis  leaves.  White,  crystalline  powder,  almost 
insoluble  in  water,  soluble  in  alcohol  and  chlorolorm. 
Dilute  acids  decompose  it  into  digitoxose,  CgHj^O^ 
(a-sugar),  and  digitoxigenin,  C22H32O.,.  Dose. 
0.00025  gm.  (jh)  grain). 

DIGITALIN,  "i'^rewc/?,"  yellow  amorphous  powder, 
soluble  in  2000  parts  of  water,  very  soluble  in  alco- 
hol and  chloroform;  consists  chiefly  of  a  glucosid, 
physiologically  identical  with  digiloxin.  Dose, 
0.00025  gm.  (y^-fl  grain). 

DIGITALIN,  ''German,^'  yellowish-white  powder, 
so'iib'e  in  water  and  alcohol,  almost  insoluble  in 
ch'oroform;  consists  of  a  mixture  of  glucosids  digi- 
talin,  amorphous  digitonin  and  digit aleln.  Dose, 
o.ooi  gm.  (^j  grain). 

DIGITALIN  cryst.  (Kiliani),  identical  with  digi- 
tonin cyst.  C27H4G^\4+SH2<^)  almost  insoluble  in 
water,  ether  and  chloroform.  Physiologically  in- 
active. 

DIGITALEIN,  while  amorphous  powder,  soluble 
in  water  and  alcohol.     A  heart  poison. 


NEUTRAL    PRINCIPLES.  50I 

QUERCITRIN,  CgeHggOjo,  is  present  in  Qiiercus 
tinctoria,  tea,  which,  when  hydrolyzed,  yields  a  yellow 
dye,  quercetin,  and  rhamnose,  a  sugar. 

EMODIN,  CjjHjqOs,  is  present  in  Cascara  sagrada, 
rhubarb  and  buckthorn  bark. 

ARBUTIN  (C12H16O7),  found  in  bearberry  leaves, 
yields  hydroquinone  and  dextrose  on  hydrolysis. 

PICROTOXIN  (CgoHg.O^a),  found  in  Cocculus 
indicus,  is  highly  poisonous. 

PODOPHYLLOTOXIN,  C.^\^^S^^  +  HjO),  occurs 
in  the  resin  of  Podophyllum  pel  latum. 


CHAPTER  XXXVI. 
THE  GUMS. 

The  gums  are  a  class  of  amorphous  substances 
frequently  produced  by  the  degeneration  of  the 
tissue  of  plant  cells.  The  gums  are  divided  into  two 
classes:  (a)  The  soluble  or  true  gums,  of  which 
ACACIA  or  gum  arabic,  an  exudation  from  Acacia 
Senegal,  is  a  type,  and  (b)  insoluble  gums,  which 
absorb  large  quantities  of  water  with  which  they 
form  jellies,  but  do  not  dissolve  in  it.  To  this  second 
class  belongs  TRAGACANTH,  from  Astragalus 
giimmijer  and  other  varieties  of  astragalus. 

ACACIA,  chemically,  is  the  arabinate  salt  of  cal- 
cium and  magnesium,  a  complex  compound,  pre- 
cipitated by  alcoholic  and  ethereal  tinctures,  ferric 
chlorid,  borax  and  lead  salts.  Its  mucilage  (Muci- 
lage acacia?)  and  powder  are  useful  for  suspending 
resinous,  fatty  or  oily  substances  in  aqueous  media, 
forming  emulsions. 

TRAGACANTH,  chemically,  is  composed  of  basso- 
rin  or  tragacanthin,  C^^W^o^io^  ^'^d  calcium  salt  of 
gummic  acid,  which  is  not  identical  with  arabic  acid. 
Tragacanth  occurs  in  flakes  which  can  be  pulverized 
when  heated  to  50°  C.  It  is  also  employed  in  making 
emulsions  and  troches  and  for  suspending  insoluble 
powders  in  water. 

502 


RESINS.  503 

RESINS  are  solid,  usually  amorphous,  vegetable 
products  with  a  conchoidal  fracture.  Soluble  in 
alcohol,  fixed  oils,  but  not  in  water.  Transparent 
or  semitransparent,  readily  fusible  and  inflamma- 
ble. Some  contain  acids,  and  with  the  alkalis 
are  capable  of  forming  soaps,  others  are  not 
saponifiable.  Composition:  Resins  are  mi.xturcs 
of  different  compounds  of  C,  O  and  H.  Shellac, 
for  example,  consists  of  5  different  resins  and  a 
coloring  matter.  Amber  is  a  mixture  of  several 
resins  with  succinic  acid.  Sandarac  consists  of 
three  insoluble  resins  and  a  bitter  principle  soluble 
in  water.  They  are,  ■  perhaps,  the  oxidation  pro- 
ducts of  volatile  oils,  judged  from  the  fact  that  they 
are  always  associated  with  it  in  plants.  Some 
resins,  like  amber,  elemi,  copal,  dammar,  kauri 
gum,  shellac  and  asphalt,  all  unofficial,  are  used 
for  the  manufacture  of  varnishes;  others,  Ukeresina, 
guaiac,  mastic,  are  used  in  medicine.  They  are 
divided  into:  (i)  Resins  obtained  from  oleoresins, 
as  the  residue  from  distillation.  (2)  Natural  exuda- 
tions. (3)  Prepared  resins  obtained  by  precipi- 
tating extracts  of  drugs  with  acidulated  water, 
sometimes  called  '"resinoids."  (4)  Balsamic  resins 
or  "balsams."  Member  of  the  first  class  RESINA, 
common  rosin  or  colophony,  is  the  residue 
after  distilling  the  volatile  oil  (oil  of  turpentine) 
from  the  oleoresin  of  turpentine  (pitch).  Melting 
point,  100°  C.  Dark,  amber-colored  mass,  soluble 
in  alcohol,  ether  and  the  oils.  Contains  abietic 
anhvdrid.     Used    mainlv    for   varnishes,  ointments. 


504  PHARMACEUTIC   CHEMISTRY. 

soaps  and  plasters.  (Off.  Prep.:  Ceratum  Resina- 
Comp.)  NATURAL  GUMS  include  all  the  varnish 
"gums"  mentioned  above  and  that  of  GUAIACUM 
(Guaiaci  resina).  It  is  found  in  the  heart  wood. 
A  very  complex  substance  consisting  of  guaiacic  acid, 
guaiac  yellow,  guaretic  acid,  betaresin,  also  small  pro- 
portion of  gum.  It  is  soluble  in  alcohol  and  caustic 
potash,  but  insoluble  in  turpentine  and  benzol.  The 
powder  is  whitish,  but  turns  green  on  exposure  to  light 
and  air,  the  depth  of  the  color  being  indicative  of  the 
age  of  the  powder.  Used  as  a  stimidant,  diuretic 
and  alterative.  Sometimes  given  as  an  emulsion 
in  rheumatism  and  in  pastils  for  sore  throat.  (Off. 
Prep.:  Tincture  and  Ammoniated  Tr.).  MASTIC 
(mastiche).  Obtained  from  vertical  incisions  into 
the  bast  layer  of  the  trunk  of  the  tree  and  the 
larger  branches.  Contains  masticJiic  acid  about 
90%,  soluble  in  alcohol;  masticin,  soluble  in  hot 
alcohol,  a  trace  of  volatile  oil.  Mild  astringent, 
also  used  for  cements  and  varnishes.  (OlT.  Prej).: 
Pil.  Aloes  and  Mastiches.)  Kauri  gum  and  amber 
(succinum)  occur  as  fossils,  so  does  asphallum. 
THE  OLEORESINS  arc  of  vcgetab'le  origin  and 
consist  of  mixtures  in  various  proportions  of  resins 
with  volatile  oil,  therefore  partaking  of  the  characters 
of  both.  They  are  divided  mto:  (i)  Natural  oleo- 
resins  to  which  belong  the  turpentines,  copaiba  and 
the  pitches.  (2)  Prepared  oleorcsins,  also  called 
pharmaceutic  oleoresins,  made  b\  extracting  oleo- 
resinous  drugs  with  ether  or  acetone.  They  are  semi- 
solid preparations  made  from  the  following  drugs: 


THE    OLEORESINS.  S05 

aspidium,  capsicum,  cubeb,  lupulin,  pepper  and 
ginger.  Copaiba,  commonly  called  "balsam  of 
copaiba,"  is  an  oleoresin  derived  from  various 
South  American  species  of  copaiba  by  Ijoring  holes 
in  the  heart  wood.  Light  to  brownish,  viscid  liquid; 
specific  gravity,  from  0.95  to  0.99,  increasing  with 
age.  Soluble  in  absolute  alcohol  and  the  other 
solvents;  insoluble  in  water.  Evaporated  on  the 
water-bath,  it  should  yield  50%  residue  and  develop 
no  odor  of  turpentine.  There  are  four  varieties  of 
copaiba:  Rio  Janeiro  and  Maranham,  containing 
volatile  oil  and  resin  in  nearly  equal  amounts. 
The  Para  variety  contains  between  70  and  85%  of 
volatile  oil,  while  Maracaibo  contains  from  20  to 
40%  of  volatile  oils  and  correspondingly  more  resin. 
This  last  variety  is  the  best  for  making  the  mass 
with  magnesia,  and  is  also  preferred  therapeutically, 
the  resin  being  most  valuable  and  the. oil  com- 
paratively inert.  Adulteration. — This  oleoresin  is 
frequently  adulterated  with  gurjun  balsam,  which  is 
detected  by  dropping  four  drops  of  copaiba  upon  a 
mixture  of  i  c.c.  of  glacial  acetic  acid  and  four  drops 
of  nitric  acid  with  which  the  adulterant  forms  a 
coloration.  The  fixed  oils,  like  castor,  cottonseed, 
turpentine  and  other  oleoresins,  are  detected  by  the 
sticky  residue  on  evaporating  the  volatile  oil. 
Volatile  oils,  like  turpentine  and  pine-needle  oils, 
are  detected  by  their  odor  w^hen  warmed.  The 
oleoresin  contains  volatile  oil,  copaibic,  oxycopaibic 
or  metacopaibic  acids,  various  resins  and  a  bitter 
principle,   soluble  in  water.     Used  as  expectorant. 


5o6  PllAKMACKUTIC    CH  K.MISTRV. 

diuretic  ;ind  stimulant  in  the  form  of  the  mixtures 
(N.  F.),  emulsion,  paste  or  pill. 

The  turpentines  are  olcoresins  from  trees  belonging 
to  the' Pimifcce  and  Conijcrce.  All  their  volatile  oils 
are  terpenes.  TEREBINTHINA,  commonly  called 
"gum,"  "pitch"  or  "common  turpentine."  It  is  a 
concrete  oleoresin,  obtained  as  an  exudation  from 
Pinus  palustris  and  other  species  of  pinus.  Yellow- 
ish, opaque,  tough  masses,  brittle  in  the  cold,  of  tere- 
binthinate  odor  and  taste,  contains  about  ^o%  of 
volatile  oil  and  about  66%  of  resin.  Used  as  diaphor- 
etic, diuretic,  stimulant  and  astringent;  externally, 
in  ointments  and  plasters.  Its  principal  use  is  for 
the  preparation  of  oil  of  turpentine  by  distillation, 
the  residue  being  common  rosin.  TEREBINTHINA 
CANADENSIS,  a  semiliquid  oleoresin  obtained  as 
an  exudation  from  the  balsam  frr  (Abies  balsamea). 
"Canada,  balsam"  and  "balsam  of  fir"  are  two  of 
its  most  common  synonyms.  Transparent,  yellow- 
ish, viscid  liquid,  hardening  with  age,  contains 
volatile  oil  and  two  resins.  It  is  used  as  a  stimulant, 
diaphoretic,  diuretic;  in  ointment  form  for  frost- 
bites; in  microscopy  as  a  mounting  "medium.  The 
unofficial  turpentines  and  pitches  embrace  the 
following:  Terebinthina  venata  (Venice  turpentine, 
Terebinihina  argentoratensis,  Strassburg  turpentine) 
closely  resembles  Canada  balsam.  Terebinthina  chia 
(Chian  or  Cyprian  turpentine),  appearance  like 
balsam  of  fir;  balsamic,  fennel-like  odor.  PIX 
BURGUNDICA  (Burgundy  pitch  U.  S.  P.  '90), 
obtained    from    -l/>/V.v    excelsa    or    N\)rway    spruce 


THE    BALSAMIC    RESINS.  507 

fir.  Semitransparent  or  opaque,  hard,  but  yielding 
without  fracture.  Fix  canadensis  (hemlock  pitch 
U.  S.  P.  '80)  resembles  the  previous  one.  Fix 
liquida,  tar  product  of  the  destructive  distillation  of 
the  wood  of  various  species  of  pine.  Viscid,  black- 
ish-brown, semifluid,  with  empyreumatic  odor,  and 
terebinthinate  taste.  Very  complex  composition. 
It  contains  the  guaiacols  and  cresols.  It  is  slightly 
soluble  in  water,  more  so  in  alcohol,  fixed  and 
volatile  oils  and  solutions  of  the  alkalis.  Used  as 
local  stimulant  and  expectorant.  (Preparations: 
Syrupus,  o.5^( ;  Ung.,  50%)-  From  this  by  distilla- 
tion is  prepared  OIL  OF  TAR  {Oleum  picis  Hqiiida;), 
specific  gravity,  0.97.  Readily  soluble,  yielding  acid 
solutions.  Dose  as  stimulant  and  expectorant,  0.2  c.c. 
Allied  to  this,  OIL  OF  CADE  (Oleum  cadinum),  a 
product  of  the  dry  distillation  of  the  wood  of 
Juniperus  oxycedrus.  A  brownish,  dark  liquid  with 
a  tarry  odor  and  taste.  Insoluble  in  water,  partially 
in  alcohol,  completely  in  ether.  Used  in  skin  diseases. 
THE  BALSAMIC  RESINS  or  "balsams."  Bal- 
sams are  oleoresins  or  gum-resins  containing  either 
benzoic  or  cinnamic  acids  or  both.  The  official 
balsams  are  benzoin,  peru,  tolu,  and  styrax.  Besides 
these,  we  have  the  balsam  of  the  sweet  gum  tree 
(liquidamber  styracifiua  of  the  southern  United 
States  and  the  dragon's  blood  (Resina  draconis), 
exudation  from  a  palm  fruit  of  Daemonorops  draco, 
native  in  Malay  Archipelago.  It  contains  both  ben- 
zoic and  cinnamic  acids.  Astringent  and  stimulant, 
emploved  for  coloring  varnishes  and  in  plasters. 


5o8  PHARMACEUTIC    CHEMISTRY. 

BENZOIN  (benzoinum),  gum  benzoin.  A  Ijab 
samic  resin  obtained  from  styrax  benzoin,  a  tree 
native  to  Sumatra,  Java  and  Siam.  It  exudes  from 
incisions  made  through  the  bark  of  tree.  Several 
varieties  known  as  the  Sumatra  benzoin,  the  Siam 
benzoin  (having  an  agreeable,  vanilla-like  odor) 
and  Penang  benzoin,  similar  to  Sumatra,  more  fre- 
quently resembling  styrax.  Benzoin  contains  from 
12  to  20%  of  benzoic  acid  which  is  obtained  by 
sublimation,  cinnamic  acids,  various  resins.  Some 
varieties  contain  vanillin.  Soluble  in  5  parts  of 
warm  alcohol,  also  in  solutions  of  the  hydroxids 
of  alkalis;  insoluble  in  water.  Antiseptic  expecto- 
rant. (Preparations:  Tr.  Benz.  20%;  Tr.  Benz. 
Comp.,  \o%;  Adeps  Benz.,  2%).  When  the  tincture 
is  prescribed  in  aqueous  solutions,  it  should  be 
emulsified  with  acacia  before  dispensing. 

BALSAM  OF  PERU  (Balsamum  peruvianum),  de- 
rived from  Toluifera  pereinie.  A  viscid,  dark  brown- 
colored  liquid,  of  an  agreeable,  vanilla-like  odor  and 
a  bitter,  acrid  taste.  Completely  soluble  in  absolute 
alcohol,  chloroform  or  glacial  acetic  acid.  Only 
partially  soluble  in  ether  and  petFoleum  benzin. 
Completely  soluble  in  5  parts  alcohol,  with  slight 
opalescence.  Specific  gravity,  1.14  to  1.15.  Con- 
tains about  6o7o  of  volatile  oil;  resin,  32%;  cinnamic 
acid,  benzoic  acid  and  benzyl  alcohol.  Frequently 
adulterated  with  alcohol,  fixed  oils,  copaiba,  turpen- 
tine and  rosin.  Used  in  ointments  internally  as 
stimulant  and  expectorant,  also  in  ])crfumery. 

BALSAM  OF  TOLU   (Balsamum  tolutanum).     A 


GUM    RESINS.  509 

balsam  obtained  from  Toluifera  balsamum  (Central 
America).  A  yellow-brown  solid,  vanilla-like  odor, 
with  a  mild,  aromatic  taste.  Completely  soluble 
in  alcohol  and  chloroform,  solutions  of  fixed  alkalis 
and  ether.  Insoluble  in  carbon  disulfid  and  benzin. 
Contains  benzoic  and  cinnamic  acids,  two  different 
resins,  toluene  and  benzylic  benzoate  and  cinnamate. 
Adulterated  with  the  turpentines  which,  with  sul- 
furic acid,  bleach,  while  the  true  balsam  turns  cherry- 
red.  Expectorant  and  stimulant.  Used  also  in  per- 
fumery. (Preparations:  Tincture  (20%);  Syrupus 
and  Tincture  Benz.  Comp.) 

STYRAX,  storax.  A  balsam  prepared  from 
the  wood  and  inner  bark  of  liquidamber  orientalis, 
a  semiliquid,  grayish,  sticky,  opaque  mass.  Upon 
standing,  separates  into  layers.  Has  an  agreeable 
odor  and  a  balsamic  taste.  Soluble  in  alcohol, 
ether  and  carbon  disulfid.  Insoluble  in  cold 
benzin,  but  hot  benzin  dissolves  out  the  styracin 
and  cinnamic  acid,  which  are  deposited  in  crystals 
on  cooling.  Composition:  Benzoic  and  cinnamic 
acids,  styracin,  storesin,  resin,  etc.  Used  as  stimu- 
lant, diuretic,  expectorant  (in  Tr.  Benz.  Comp.). 

GUM  RESINS  comprise  those  milky  exudations  of 
plants  which  contain  gums,  soluble  in  water,  and 
resins,  insoluble  in  water,  but  soluble  in  alcohol. 
Some  contain  volatile  oils;  therefore,  they  are 
divided  into  (i)  Those  containing  volatile  oil: 

ASAFETIDA  (asafoetida).  Exudation  product 
from  Ferula  foetida  and  other  species  of  Ferula. 
Native   of   Afghanistan   and   Turkistan.     Obtained 


5IO  PHARMACEUTIC    CHEMISTRY. 

by  incision.  Several  varieties  are  known,  like  the 
amygdaloid,  coming  in  irregular  pieces  or  tears 
imbedded  in  a  sticky,  brownish  mass.  The  liquid, 
which  is  a  sticky,  semifluid  or  more  or  less  impure 
mass,  which  darkens  on  exposure,  and  the  stony 
variety,  which  contains  a  large  proportion  of  calcium 
sulfate  and  other  impurities.  Asafetida  possesses  a 
strong,  garlic-like  odor,  bitter  acrid  taste,  forms  a 
milky  emulsion  with  water,  which  turns  yellowish  with 
ammonia.  Asafetida  should  yield  not  less  than  50% 
of  matter  soluble  in  alcohol.  Composition:  vola- 
tile oil,  3  to  9%;  gum,  20  to  30%;  resin,  50  to  70%, 
and  various  impurities.  Stimulant,  antispasmodic, 
expectorant.  (Preparations:  Emulsum,  4%;  Tr., 
20%;  Pil.  Asaf.)  Usually  administered  in  pills, 
suppositories  or  emulsion. 

MYRRH  (myrrha).— Spontaneous  exudation  from 
bark  of  Commiphora  myrrha  (Arabia).  A  dusty 
reddish  or  brownish  mass  of  irregular  tears;  aromatic 
odor;  bitter,  acrid  taste.  It  yields  a  brownish-yellow 
emulsion  with  water.  Its  alcoholic  solution  acquires 
a  purple  coloration  with  nitric  acid.  It  is  composed 
of  gum,  40  to  6o'>^  ;  resin,  25  to  40%;  a  trace  of  vola- 
tile oil  and  a  bitter  principle.  Used  as  a  stimulant, 
expectorant.  (Preparations:  Mixt.  Ferri  Comp., 
Pil.  Aloes  et  Myrrh,  Tr.  Aloes  et  Myrrh).  Usually 
administered  in  pill  or  powder  or  as  an  emulsion. 
The  unofficial  gum  resins  containing  volatile  oil  are: 
Bdellium,  very  s\m'i\ar  io  myrrh;  olibanum  (frankin- 
cense), which  contains  about  30%  of  gum,  70^1  of 
resin,  with  volatile  oil  and  i)ittcrs.     Used  in  plasters 


GUM    RESINS.  511 

and  fumigations;  AniDioniaatDi,  ammoniac  (sjjon- 
taneous  exudation  product  from  the  stem  of  Dorema 
ammoniacum  U.  S.  P.  '90),  contains  gum,  18  to 
25%;  resin,  70%;  volatile  oil,  from  ^  to  4%.  Used 
as  expectorant  and  stimulant  for  making  Emuls. 
Ammon.  Oppoponax,  similar  in  properties  and  uses 
to  ammoniac;  Galbamim,  spontaneous  exudation,  of 
which  there  are  two  kinds — the  tear  and  lump 
galbanum.  Its  alcoholic  solution,  treated  with  HCl, 
turns  purplish.  It  contains  20%  of  gum,  66%  of 
resin,  volatile  oil,  6  to  g'oj .  Used  as  antispasmodic, 
stimulant,  expectorant. 

(2)  Gum  resins  containing  no  volatile  oils:  CAM- 
BOGIA  (gamboge),  obtained  by  making  incisitms  into 
the  bark  of  Garcinia  hanburii  (Cochin  China  and 
Siam).  Cylindrical  sticks,  sometimes  hollow,  con- 
choidal  fracture,  orange-red  in  color;  odorless; 
acrid,  unpleasant  taste;  the  dust  being  sternutatory. 
Good  quality  yields  a  bright  yellow  powder,  also 
bright  yellow  emulsion  with  water.  Composition: 
gum,  16  to  20%;  resin,  about  80%.  Used,  com- 
bined with  other  drugs,  as  a  hydragogue  cathartic. 
(Preparation:  Pil.  Cathart.  Comp.)  SCAMMO- 
NIUM  (scammony).  The  dried  milk-juice  of  Con- 
volvulus scammonia  (Western  Asia).  Obtained  by 
cutting  off  the  top  of  the  root  and  collecting  the  milky 
juice.  Dark  greenish  or  l)lackish,  irregular  masses, 
l)reaking  with  an  angular  fracture.  .\  resinous 
luster;  the  powder  has  a  greenish  cast.  With  water  it 
\ields  a  dark  greenish  emulsion.  Odor,  checsc-like; 
taste,  acrid.  Composition:  Gum,  5  to  i59(  ;  resin, 
33 


512  PHARMACEUTIC   CHEMISTRY. 

80  to  9o'/c ;  frequently  adulterated  with  starch,  chalk 
and  various  resins.  Used  as  hydragogue  cathartic. 
(Preparation:  Resina  scammonii).  Usually  adminis- 
tered in  pill  form.  ELASTICA  (rubber,  caoutchouc). 
The  prepared  milk-juice  of  Hevea  brasiliensis 
and  of  various  other  species  of  Hevea.  Known  in 
commerce  as  Para  rubber.  Obtained  by  evaporat- 
ing the  milk-juice  and  exposing  the  semi-solid  to  fire 
and  smoke  until  hard  masses  or  "hams"  are  formed. 
Brown  or  brownish-black,  internally  lighter  colored; 
insoluble  in  water,  dilute  acids,  solutions  of  alkalis 
or  alcohol;  but  soluble  in  chloroform,  benzene  and 
benzin,  carbon  disulfid  and  oil  of  turpentine.  Lighter 
than  water.  Melting-point,  125°  C,  and  at  this 
temperature  dissolves  in  petrolatum.  With  carbon 
disulfid  it  iorms  a  mass  used  as  rubber  cement. 
The  50%  solution  in  petrolatum  with  lead  plaster 
constitutes  the  rubber  adhesive  plaster.  Mixed  with 
sulfur  and  heated,  it  is  rendered  insoluble  and  un- 
affected by  heat,  or  vulcanized  (vulcanite  or  ebonite 
or  hard  rubber).  EUPHORBIUM,  an  official  ex- 
udation from  incisions  in  the  stem  of  Euphorbia 
resinifera  or  cactus-like  shrub,  is  native  to  Morocco. 
It  has  an  acrid  taste,  a  brownish-yellow  color, 
occurring  in  globular  or  irregular  masses;  not 
completely  emulsified  with  water  nor  completely 
soluble  in  the  simple  organic  solvents.  It  contains 
euphorbin,  a  resin,  18%  of  gum  and  impurities. 
Used  as  a  violent  purgative. 


NAPHTHALENE    AND    ITS    DERIVATIVES.  513 

NAPHTHALENE  AND  ITS  DERIVATIVES. 

Naphthalene  has  the  formula  QoHg,  a  melting- 
point  of  80°  C.  and  a  boiling-point  of  218°  C.  It 
occurs  in  that  portion  of  coal-tar  which  boils  between 
180  and  220°  C,  and  which  on  cooling  solidifies 
to  a  mass  of  crystals  constituting  crude  naphthalene. 
Crude  naphthalene  is  warmed  with  caustic  soda,  to 
remove  phenol,  next  with  a  little  sulfuric  acid,  to 
remove  the  bases,  distilled  with  steam,  separated 
and  dried.  It  is  sometimes  further  purified  by 
sublimation. 

Properties.- — Naphthalene  is  insoluble  in  water, 
but  dissolves  readily  in  the  organic  solvents.  By 
heating  it  to  130°  with  dilute  nitric  acid,  it  is  oxidized 
to  phthalic  acid;  hydriodic  acid  will  gradually  reduce 
naphthalene  to  dihydrid,  CjoHjo,  tetrahydrid,  CioHjj, 
and  hexahydrid,  C^^Yi^^.  With  nascent  chlorin  it 
forms  additive  products:  Dichlorid,  CjoHgClj,  tetra- 
chlorid,  CioHgCl^,  etc. 

Structure. — Various  structural  formulas  were  from 
time  to  time  advanced  for  naphthalene;  thus: 

CH       CH 


HC 


I 
C<',^lcH 
CH       CH 


Bamberger's  centric  formula 


514 


PHARMACEUTIC   CHEMISTRY. 


H     H 

I        I 
C      C 


H— C      C      C— H 

I       II       I 
H— C      C      C— H 


C      C 

I        I 
H     H 


Erlenmeyer's  formula 


Both  of  the  above  formulas  have  something  in 
their  favor;  however,  the  Erlenmeyer  formula,  based 
upon  Kekule's  alternate  single  and  double  bond- 
benzene  rings,  is  now  generally  accepted. 

From  the  Erlenmeyer's  formula  for  naphthalin  it 
may  be  regarded  as  two  Ix-nzene  rings  having  two 
carbon  atoms  in  common. 


^^\/\ 


The  more  compactly  written  formula 


is  now  generally  used  in  the  text-books  on  organic 
chemistry.    Naphthalene  gives  two  mono-derivatives 

which  arc  distinguished  by  the  prefixes  a  (alpha) 
and  P  (beta).  The  structural  formula  for  nai)htha- 
Icne  shows  this,  on  numbering  the  carbons  in  (he 
nucleus;  thus: 


SYNTHESIS    OF    NAPHTHALENE. 


515 


.    The  sulistitution  can  either  take  place 


at  one  of  the  carbon  atoms  which  is  attached  to 
one  of  the  two  carbon  atoms  common  to  both  rings; 
thus,  I,  4,  5  and  8,  giving  an  alpha  compound,  while 
2,  3,  6  and  7  give  a  beta  compound. 

Synthesis. — Naphthalene  may  be  synthesized  by- 
passing phenylbutene  bromid  over  red-h(_)t  lime. 

CgHs.C.H.Br^    =    2HBr    +     QpH^     +   H2 

naphthalene 

Homologues. — Two   methylnaphthalenes  and   two 
ethylnaphthalenes  are  known.     Of  these  ^-methyl- 


naphthalene. 


CH3 


is  a  solid,  melting  at 


32°   C;  the  other  thi-ee  compounds  being  liquids 
with  high  boiling-points. 

When  naphthalene  is  heated  with  sulfuric  acid, 
two  mono-sulfonic  acids  are  formed.  These  acids, 
fused  with  caustic  alkalis,  similarly  with  the  produc- 
tion of  phenol  from  benzene,  yield  two  hydroxy- 
naphthalenes : 


5i6 


PHARMACEUTIC    CHEMISTRY. 

OH 


and 


OH 


alpha-naphthol  melt- 
ing-point, 95°;  boil- 
ing-point, 282°  C. 


beta-naphthol  melting- 
point,  122°;  boiling- 
point,  288°  C. 


THE  NAPHTHOLS  are  hydroxids  of  the  monoval- 
ent radical  naphthyl,  CjoHy,  and  bear  the  same 
relation  to  naphthalene  that  phenol  bears  to  benzene. 

ALPHA-NAPHTHOL,  CioH^OH,  is  used  as  an 
antiseptic  and  antifermentative,  but  being  more 
toxic  is  less  used  than — 

BETA-NAPHTHOL,  CioH^— OH,  is  generally  used 
as  an  antiseptic  in  cutaneous  disorders  as  an  oint- 
ment. It  is  soluble  in  aqueous  solutions  of  alkali 
hydroxids,  forming  metallic  derivatives. 

ORPHOL, Basicbeta-nafhthol bismuth  (CioH-OjjBi 
+   3H2O,   a  brownish   powder   possessing   an  aro- 
matic odor  and  containing  about  72.5%  of  bismuth 
oxid.     Used  as  intestinal  astringent. 
^COOH 

EPICARIN,  C«H3— OH  ,  is  beta-naphthyl- 

^CH^.O.C.oHj 
ortho-oxymetatoluitic  acid,  a  brownish-yellow 
powder,  sparingly  soluble  in  hot  water,  but  freely  in 
alcohol,  ether  and  acetone.  It  is  employed  similarly 
to  /3-naphthol  in  skin  diseases,  but  is  said  to  be 
superior  to  it. 


NAPHTHYLAMIN    COMPOUNDS.  517 

NAPHTHYLAMINS.— The  two  naphthylamins, 
CjqH^.NH,,  resemble  anilin  closely  and  are  prepared 
by  similar  methods. 

ALPHA-NAPHTHYLAMIN,  CioH^.NH.,  is  ob- 
tained by  heating  ammonia  and  a  naphthol  with 
calcium  chlorid  to  250°  C: 

C,oH,OH  +  NH3  =    C10H7.NH2   +  H2O. 

a  naphthylamin 

melting-point,  50°; 

boiling-point, 

300°  C. 

It  can  also  be  obtained  by  reducing  a  nitronaph- 
thalene  with  nascent  hydrogen.  It  occurs  in  crystal- 
line needles  (Zinin,  1842). 

BETA-NAPHTHYLAMIN  is  best  obtained  by 
acting  on  iS-naphthol  with  ammonia  under  pressure. 
i3-Naphthylamin  melts  at  112°  and  boils  at  294°  C. 

NITRONAPHTHALENES.— By  the  direct  nitra- 
tion of  a-naphthol  only  the  a-nitrona phthalene  is 
obtained.     It  has  the  melting-point  61°  C. 

The  second  nitro  group  likewise  enters  the  alpha 
(i  and  4)  position,  consequently  it  is  not  possible  to 
prepare  beta-nitronaphihalene  by  any  direct  method. 

Beta-nitronaphthalene  is  obtained  from  i3-naph- 
thylamin  by  the  diazo-reaction.     It  melts  at  79°  C. 

NAPHTHALENE  SULFONIC  ACIDS,  C10H7.SO3H, 
are  formed  when  naphthalene  is  heated  with  strong 
sulfuric  acid.  The  ordinary  naphthalene  sulfonic 
acid  is  a  mixture  of  both  the  alpha  and  beta  varieties. 
These  vary  in  ratio  to  each  other  with  the  temper- 


5l8  PHARMACEUTIC   CHEMISTRY. 

ature  of  the  reaction;  thus:  At  a  temperature  not 
exceeding  80°  mostly  the  alpha  is  formed,  while  at 
160°  C.  the  beta  acid  predominates. 

When  fused  with  potash,  these  acids  are  decom- 
posed into  the  corresponding  naphthols. 

NAPHTHYLAMIN  SULFONIC  ACIDS  are  em- 
l)loyed  in  the  manufacture  of  such  azo  dyes  as  congo 
red — henzopiirpiirin,  etc. 

NAPHTHIONIC  ACID  (i  and  4)  is  obtained  jjy 
heating  in  vacuo  a-naphthylamin  sulfate  to  130°  C; 
it  has  the  formula  CioH,.(NH2)S03H. 

MARTINS'  yellow' is  obtained  by  acting  with 
strong  nitric  acid  u])()n  a-naphthol.  The  sodium 
salt,  C,oH-,(()H).>()Na,H20,  is  used  as  a  dye. 

NAPHTHOL  YELLOW  is  ol)tained  by  acting  with 
strong  nitric  acid  ujxm  a-naplithol-lrisulfonit-  acid. 
The  potassium  salt  is  used  as  a  dye. 

NAPHTHAQUINONES.— Two  isome;s  are  known, 
of  which  a-najjhthaquinone  corresponds  to  benzo- 
(juinone  in  properties.     Their  formula  is  CjoHgC^^- 

NAPHTHOIC  ACIDS.— Naphthalene  forms  also 
the  unini])ortant  carboxylic  acids,  of  which  the  two 
known  ones  will  l)e  given: 

(/-NAPHTHOIC  ACID,  CioHj.COOH,  obtained  by 
the  hydrolysis  of  the  a-cyanid  CiqH^.CN;  melts  at 
160°  C. 

/i-NAPHTHOIC  ACID,  prepared  from  the  /3-cyanid ; 
melts  at  182°  C. 

NAPHTHALIC  ACID,  C,oHe(COOH),,  has  the  two 
carbowis  in  per: position  (both  in  alj)ha  i,  8). 


STRUCTURAL    FORMULAS. 

Structural  jormulas: 

OH 


519 


OH 


naphthalene,  CioHs 

NH, 


o-naphthol 
C10H7.OH 


6-napthol 
C10H7.OH 


NO2 


NH. 


a-naphthylamin 
C10H7.NH2 


6-naphthylamin  a-nitronaphthalene 

B10H7.NH2  CioH7.N02 

OK 


SO3H 


NO, 


SO,K 


NO, 


6-nitronaphthalene     a-naphthalene-sul-  naphthol  yellow 

C10H7.NO3  fonicacid  CioH6(N02)20.Na 

C10H7.SO3H 
O  O 

II  II         COOH       COOH 


6-naphthaquinone  napthalic  acid 

CioH6(COOH)2 


a-naphthaquinone 
C10H6O2 


520 


PHARMACEUTIC   CHEMISTRY. 


ANTHRACENE.— 

Anthracene,  Cj^Hjo,  occurs  in  that  fraction  of  the 
heavy  coal-tar  oil  which  boils  between  230°  and 
270°  C.  It  is  found  as  a  light  brown  deposit,  mixed 
with  phenanthrene  and  carhazole.  This  sediment  is 
separated  by  means  of  a  filter  press  and  the  residue 
is  washed  free  from  oil,  with  naphtha.  The  product 
contains,  and  is  known  in  commerce  as,  "  50  per 
cent."  anthracene.  From  this  crude  anthracene 
alizarin  and  other  valuable  dyes  are  made. 

By  mixing  the  crude  anthracene  with  solid  potas- 
sium hydroxid,  it  combines  with  carbazole,  forming 
potassium  carbazole,  and  the  residue  with  carbon 
disulfid,  with  which  phenanthrene  (more  soluble) 
can  be  washed  out. 

Properties. — Anthracene  occurs  in  colorless  plates, 
having  a  bluish  fluorescence,  melting  at  213°  and 
boiling  at  351°  C.  It  is  insolul)le  in  water,  but 
readily  soluble  in  the  organic  solvents. 

Structure. — Naphthalene  is  frequently  regarded  as 
a  condensation  of  two  benzene  rings  with  the  loss  of 
two  carbon  atoms;  just  so,  anthracene  may  be 
regarded  as  a  condensation  of  three  benzene-rings 
with  the  loss  of  four  carbon  atoms: 


\, 


c 


C 

II  I 

c      c 


or,  more 
compactly, 


Synthesis. — Anthracene    may   be    synthetized    by 


SUBSTITUTION   PRODUCTS    OF   ANTHRACENE.  52 1 

passing  petroleum  through  red-hot  tubes;  also  by 
heating  benzyl  chlorid  with  aluminum  chlorid: 
3C6H5CH,C1  =  C6H4  =  CH-CH  =  C6H,  +  CeH,  CH,  +  HCl. 

anthracene  toluene 

SUBSTITUTION  PRODUCTS.— Three  isomeric 
monosubstitution  p  oducts  of  anthracene  are  pos- 
sible; these  can  be  distinguished  by  prefixing  their 
names  with  the  Greek  letters  a,  /3  or  7: 

a         y  a 


also  fifteen  disubstitution  products. 

ANTHRAQUINONE.— With  the  exception  of  an- 
thraquinone  and  its  hydroxids,  the  products  of  an- 
thraquinone  are  of  little  pharmaceutic  importance. 

Anthraquinone,  C14H8O2,  is  prepared  by  oxidizing 
anthracene  with  chromic  acid.  It  occurs  in  yellow, 
insoluble  prisms,  which  dissolve  in  benzene;  melt  at 
285°  C,  and  at  higher  temperatures  sublime. 

With  hydriodic  acid  it  is  reduced  to  anthracene. 

Structure: 

O 


CO 


522  PIIAR.MACEUTIC    CHEMISTRY. 

HYDROXYANTHRAQUINONES.— The  «-  p-dihy- 
droxyanthraquinone  is  the  very  im])()rtant  dve  alizarin, 

.CO. 
CgH/         ^CeH,(OH),.     Alizarin  occurs  naturallv 

\co/ 

in  the  madder  root  (Rubia  tinctoria)  as  ruberythric 

acid,  and  has  from  early  times  been  employed  as  a 

red  dye-stufif.     Alizarin  is  one  of  the  most  important 

dyes  in  the  entire  gallaxy  of  dyes.     It  is  also  one  of 

the  most  important  synthetic  economic   discoveries 

(Perkin,   Graebe  and  Liebermann,  1868)  of  all  the 

times. 

It   was  originally  synthesized  l^y  fusing  dibrom- 

anthraquinone  with  caustic  potash: 

/CO\ 
Qh/         ;CeH.Br.    +    2KOH    = 

\co-^      '    ' 

dibromanthraquinone 

QH/         )C6H..(0H),    +    2KBr. 
^CO^ 

alizarin. 

Synthesis. — The  above  method,  proving  too  costly, 
was  later  relinquished  for  another  process,  consisting 
in  the  heating  of  anthraquinone  with  pyrosulfuric 
acid  to  160°  C.  and  forming  anthraquinone-beta- 
suljonic  acid: 

CO. 
CeH,(         >CeH,  +  H,SO,  = 


'^CO' 


anthraquinone 

.CO. 


C„H,(         )C«H3  -  SO3H  +  H,0. 
^CO-^ 

anthraquinone  b-sulfonic  acid 


ALIZARIN.  523 

This  acid  is  neutralized  with  sodium  carbonate 
and  the  so-formed  sodium  salt  is  fused  with  caustic 
soda  and  a  little  potassium  chlorate,  the  chlorate 
furnishing  the  necessary  oxygen: 
CO 
CeH,/  )C6H3.S03Na  +  NaOH  +  0  = 

CO 
C,H,(         >CeH,(OH)3  +  Na2S03. 
^CO-^ 

alizarin 

The  alizarin  formed  is  dissolved  out  in  water, 
digested  with  milk  of  lime,  and  insoluble  calcium 
alizarate  is  filtered  out.  This  calcium  salt  is  next 
decomposed  with  hydrochloric  acid,  whereupon  the 
alizarin  precipitates  as  a  brown,  amorphous  powder. 
It  is  sent  into  commerce  as  a  10  or  20%  alizarin  paste. 

Properties. — Alizarin  is  insoluble  in  water,  but 
dissolves  in  the  caustic  alkalis  with  a  violet  color, 
forming  corresponding  alkali  salts.  This  violet 
color  is  bluer  in  the  presence  of  NaOH,  and  redder 
if  NH^OH  is  present. 

With  the  metallic  compounds  it  forms  insoluble 
compounds  of  different  colors,  called  "lakes;"  thus, 
with  the  ferric  salts  a  "violet  lake";  with  chromium 
salts,  "brown  lakes";  with  aluminum  salts,  "bright 
red  lakes";  with  barium  chlorid,  "deep  purple 
lake";  with  stannous  chlorid,  "orange  lake."  These 
alizarates  can  be  precipitated  with  ammonium 
hydroxid,  collected,  dried  and  used  as  pigments; 
thus,  with  aluminum  acetate  the  familiar  turkcy-rcd 
is  obtained. 


524 


PHARMACEUTIC   CHEMISTRY. 


In  1880,  $8,000,000  worth  of  alizarin  had  been 
made  artificially.  Had  this  same  amount  of  alizarin 
been  made  from  madder  root,  the  cost  of  the  neces- 
sary material  alone,  irrespective  of  labor,  would 
have  been  $28,000,000.  Thus  a  saving  of  $20,000,- 
000  had  been  effected  in  one  year  by  one  synthetic 
chemical  method. 

Alizarin  orange  and  alizarin  blue  are  some  of  the 
alizarin  derivatives. 

PURPURIN  (i,  2,  4),  trill ydroxya nth raquinone, 
occurs,  like  alizarin,  in  the  roots  of  the  various  species 
of  rubia,  and  it  can  be. obtained  from  alizarin  by 
heating  it  with  manganese  dioxid  and  sulfuric  acid. 
It  occurs  in  yellowish-red,  slightly  hot-water-soluble 
prisms.  In  the  presence  of  mordants,  it  dyes  fabrics 
a  yellowish-red  color. 

ANTHRAPURPURIN  (i,  2,  2'),  trili ydroxya nthra- 
quinone,  is  obtained  by  fusing  1,2'  disulfonic  acid 
with  caustic  soda  and  potassium  chlorate. 

FLAVOPURPURIN  (i,  2,  3'),  trihydroxyanthra- 
quinone,  is  formed  in  a  similar  way  to  anthiapurpurin 
from  I,  3'  anthraquinone  sulfonic  acid. 

Structure: 


O 


\/  \/ 


anthracene 


0 


anthraquinone 


PHENANTHRENE. 


525 


O   OH 


OH 


O   OH 


OH 


O 


O   OH 


HO 


OH 


OH 


O   OH 


HO 


OH 


O 


anthrapurpurin 


flavopurpurin 


PHENANTHRENE,  C,,U^„  is  isomeric  with 
anthracene,  and  is  found  in  coal-tar  associated  with 
it.  It  occurs  in  colorless  needles,  melting  at  99° 
and  distilling  at  340°  C. 

Phenanthrene  is  regarded  chemically  as  diphenyl 


C12H10,    in  which  the    two  ortho- 


positions  are  linked  by  the  group  —  CH  =  CH 
thus: 


526  I'HARMACEUTIC    CHKMISTRY- 

CH      c^}tzz::^^c      ch 


HC(  > V  ;cH 

CH       CH  CH       CH 

or,  more  compactlv, 


Phenanthrene  is  of  little  commerical  or  pharmaceutic 
importance. 


CHAPTER  XXXVII. 

HOMOCYCLIC  AND  HETERO-CYCLIC 
SUBSTANCES. 

All  the  ring  (cyclic)  structures  thus  far  studied 
have  been  composed  of  similar  atoms,  namely, 
carbon.  Thus,  benzene,  naphthalene,  anthracene, 
have  only  carbon  in  their  rings;  such  substances  are 
called  homocyclic. 

There  are  known,  however,  compounds  having 
two  or  more  dissimilar  atoms  in  their  rings,  these  are 
known  as  heterocyclic  substances.  An  important 
example  of  this  latter  class  is  had  in  pvridin, 
C,H,N. 

PYRIDIN,  C5H5N,  is  a  colorless  liquid  with  an 
odor  like  tobacco  smoke  and  a  boiling-point  of 
115°  C. 

Pyridin  occurs  in  bone  oil,  "Dippel's  oil,"  pro- 
duced by  the  destructive  distillation  of  bones.  The 
fraction  passing  at  150°  is  collected  and  converted 
into  pyridin  ferrocyanid,  which  is  purified  bv 
recrystallization  and  decomposed  by  the  alkalis. 
Pyridin  is  soluble  in  water.  When  treated  with 
metallic  sodium  in  an  alcoholic  solution,  it  is  con- 
verted into  piperidin,  CjHuN. 

With  the  halogens  it  forms  substitution  products, 
and  under  certain  conditions  also  addition  products. 
34  527 


528 


PHARMACEUTIC    CHEMISTRY. 


With  acids  pyridin  forms  staljle  crystallizable 
salts  by  addition,  thus  proving  its  amin  nature.  It 
is  not  acted  upon  by  nitrous  acid,  nor  is  it  converted 
into  isonitril  by  alcoholic  potash  and  chloroform, 
proving  that  it  is  a  tertiary  amin,  having  the  structure 


H 

\ 

H— C    ^/3C— H 


H— C       «C— H 

pyridin,  boiling-point. 


or,  more  compactly. 


/\ 


N 


This  structure  is  verified  by  its  synthesis  from 
penta-methylene-diamin  hydrochlorid.  By  rapidly 
heating  this  latter  salt,  it  loses  one  molecule  of 
NH^Cl,  becoming  converted  into  piperidin,  the 
hexahydrid  of  pyridin.  This,  by  mild  oxidation,  is 
converted  to  pyridin: 


CH2 


HX      CH, 


H2C 


CH., 

I        I 
NH.,NH.,.HC1 


pentamcthylene 
diamin-hydrochlorid 


H,C 


H..C 


CH, 


CH, 


CH, 


NH 


jiiperidin 


PYRIDINCARBOXY  ACIDS. 


529 


CH 

HC  ^^  CH 


HC 


CH. 


N 


pyridin 

Regarding  the  situation  of  the  carbon  atoms  to 
the  nitrogen  atom,  it  is  apparent  that  it  should  form 
three  isomeric  mono-substitution  products,  and  in 
reality  three  such  isomerids  are  known  in  the  three 
pyridincarboxy  acids;  thus: 


(a)  picolinic  acid  (;3)  nicotinic  acid 


(7)  isonicotinic  acid. 

COOH. 


COOH 


COOH 

N  N  N 

Pyridin  has  several  homologues:  The  methyl 
pyridins,  known  as  picolins;  dimethylpyridins, 
known  as  lutidins;  and  trimethylpyridins,  known 
as  collidenes. 

QUINOLIN,  C9H7N  (Gerhardt,  1842),  like  pyridin, 
occurs  in  bone  oil  and  coal-tar  oil.  It  can  be 
synthesized  by  boiling  together  a  mixture  of  anilin, 
nitrobenzene,  glycerol  and  sulfuric  acid,  removing 
the  undecomposed  nitrobenzene  by  steam,  rendering 
alkalin  and  separating  the  quinolin  with  a  current 
of  steam. 


530 


'HARMACEUTIC    CHEMISTRY. 


Quinolin  is  a  colorless  oil  with  an  unpleasant 
penetrating  odor,  sparingly  soluble  in  water  and 
boiling  at  239°  C.  It  combines,  like  pyridin,  with 
the  acids,  and  exhibits  all  the  other  properties  of 
tertiary  amins. 

Upon  oxidation,  quinolin  is  first  converted  into 
tetra-  and  finally  into  decahydroquinolin.  With 
potassium  permanganate  it  is  oxidized  into  quino- 
linic  acid. 


COOH 


COOH 


COOH 
COOH 


N 


quinolin,  boiling- 
point,  "^32  C. 


quinolin ic  acid, 
(a.|3.  pyridin  dicar- 
boxy  acid.) 


ISOQUINOLIN,  C9H7N,  occurs,  like  (juinolin,  in 
bone  oil  (Hoogewerfif).  It  was  first  obtained  from 
crude  quinolin  by  fractional  crystallization  of  the 
sulfate.  It  occurs  in  crystals,  melting  at  21°  and 
boiling  at  237°  C. 


NH 


isoquinolin,   boil- 
ing-point, 237' C. 


carbazole,   me  1 1  j  n  g  ■ 
point,  338°  C. 


THE   ALKALOIDS.  53 1 

CARBAZOLE,  QjIigN,  occurs  with  anthracene 
in  anthracene  grease.  Melting-point,  238°;  boiling- 
point,  351°  C. 

THE  ALKALOIDS. 

Some  of  the  basic  substances  already  mentioned, 
as  pyridin,  quinolin  and  isoquinolin,  are  usually 
considered  as  the  simpler  alkaloids. 

Alkaloids  are  now  frequently  classified  with  refer- 
ence to  their  parent  body;  i.  e.,  body  of  which  they 
are  considered  derivatives;  thus: 


DERIVATIVES    OF  PYRIDIN, 


N 

Lobeline,  C^^H^J^^j  from  Indian  ttjbacco  (Lobelia 
inflata). 

Sparteine,  CijHjgNj,  from  broom  (scoparius). 

Piperidine,  CjHuN,  found  in  pepper  (Piper 
nigrum). 

Coniine,  CgHj^N,  found  in  poison  hemlock  (Conium 
maculatum),  a  liquid  alkaloid,  boiling  at  167°  C. 

Nicotine,  QoHi^Nj,  from  tobacco  (0.6  to  8%) 
(Nicotiana  tabacum). 

Piperine,  C17H19NO3,  found  in  pepper  (8%). 

Atropine,  C17H23NO3,  found  in  belladonna  (Atropa 
belladonna),  thorn-apple  (Datura  strammonium), 
henbane  (Hyoscyamusniger).     It  melts  at  115°  C. 

Hyoscyamine,  C17H23NO3,  found  associated  with 


532  PHARMACEUTIC   CHEMISTRY. 

scopolamine  in  the  plants  of  the  deadly  nightshade 
family.  It  melts  at  108.5°  C,  and  at  this  temper- 
ature becomes  converted  into  the  isomeric  alkaloid 
atropine. 

Scopolamine,  found  in  the  plants  of  the  "deadly 
nightshade"  family  and  purported  to  constitute  the 
bulk  of  the  hyoscine  of  commerce,  with  which  it  is 
said  'to  be  identical.  This  last  statement  should  be 
treated  with  some  skepticism  until  more  is  known 
of  the  structure  of  these  alkaloids;  scopolamine  melts 
at  198°  C. 

Hyoscine,  C^-^l^n^^O^,  found  in  the  plants  of  the 
deadly  nightshade  family. 

Homatropine,  C,eH2iN03,  an  artificial  alkaloid — 
tropine  mandelate. 

The  last-mentioned  five  alkaloids  constitute  the 
class  of  "mydriatic  alkaloids,"  capable  of  dilating 
the  pupil  of  the  eye.  Homatropine  is  deemed  the 
most  desirable,  since  its  mydriasis  wears  off  in 
twenty-four  hours. 

Cocaine,  Ci7H,jNOj,  occurs  associated  with  eight 
closely  related  alkaloids  in  coca  leaves  (Erythroxyl- 
lon  coca).  Cocaine  also  exerts  a  slight  mydriatic 
action,  but  is  chiefly  employed  as  a  local  anesthetic. 
It  melts  at  08°  C. 


DERIVATIVES  OF  QUINOLIN, 


N 


STRUCTURE    OF    QUININE. 


533 


Quinine,  C^oHj^NjOj,  found  with  utlier  alkaloids 
in  cinchona  bark  (Cinchona  calisaya)  and  other 
varieties  of  cinchona  (8  to  io%) .  It  is  a  diatomic  base 
and  forms  two  classes  of  salts;  melts  at  177°  C. 

Cinchonine,  CjgHjjNsO,  found  associated  with 
quinine  (2.5%.)  It  is,  like  quinine,  dibasic  and  forms 
two  classes  of  salts;  it  melts  at  250°  C. 

Qiiinidine  and  cinchonidine  are  two  other  alkaloids 
of  cinchona,  distinguished  from  the  former  two  by 
being  dextrogyrate  and  forming  soluble  tartrates. 

Quinine  and  cinchonine  are  levo gyrate;  and  form 
sparingly  soluble  tartrates.  To  detect  whether 
quinine  or  its  salts  are  contaminated  with  the  cheaper 
cinchona  alkaloids,  it  should  readily  dissolve  in 
ammonia  water;  the  other  alkaloids  do  not. 


Structure: 


C,oH,5(OH)N 


CH3O 


N 


quinine 

Morphine,  CJ7H19NO3.H2O,  found  in  opium  (from 
Papaver  somniferum)  together  with  twenty  other 
alkaloids,  as  follows;  morphine,  10%;  narcotine,  6%; 
papaverine,  1%;  codeine,  0.5%;  thebaine,  0.3%; 
narceine,  0.2%,  etc.;  separated  by  Sertiirner. 

It  melts  at  230°,  and  is  a  strong  narcotic. 

Codeine,  CjgHjiNOg,  is  a  homologue  of  morphine, 


534  I'llARMACEUTIC    CHEMISTRY. 

and  found  associated  witli  it.  It  melts  at  153°  (". 
and  is  the  most  soluble  of  ojjium  alkaloids. 

Strychnine,  C21H22N2O2,  found  in  the  "dog-button" 
(Strychnos  nux  vomica)  and  other  strychnos  species. 
It  melts  at  284°,  is  a  monacid  base;  sparingly 
soluble  in  water,  readily  in  the  acids.  Very  strongly 
poisonous,  producing  tetanus  even  in  small  doses. 

Brucine,  C23H26N2O4,  crystallizes  in  colorless 
prisms  and  melts  at  178°  C.  Sparingly  soluble, 
monacid  base. 

Colchicine,  C2iH22(CH30)N05,  found  in  Colchicum 
autumnale.  Amorphous  alkaloid,  melting  at  147°  C. 
When  hydrolyzed,  it  yields  a  second  alkaloid, ro/r/n- 
cein,  C21H22OHNO5. 

Physostigmine,  Ci5H2iN302,  also  called  eserin; 
found  in  calabar  bean  (Physostigma  venenosum). 
While  the  alkaloids  of  the  deadly  nightshade  family 
are  all  mydriatic,  the  opium  alkaloids  are  all  myotic 
(contracting  the  pupil  of  the  eye);  but  the  strongest 
myotic  is  found  in  physostigmine. 

Pilocarpine,  C11H16N2O2,  found  in  jaborandi  leaves 
(pilocarpus).  It  is  a  deliquescent  alkaloid,  very 
soluble,  used  to  produce  diaphoresis.   " 

Veratrine,  C37H53NO11,  found  in  cevadilla  seed 
(Asagrea  otTicinalis),  and  not  from  veratrum,  as  is 
erroneously  supi)Osed.  It  is  poisonous  and  a  power- 
ful sternutatory. 

THE  DERIVATIVES  OF  XANTHIN  have  been  con- 
sidered on  page  3Q2,  and  embrace  theine,  caffeine 
which  is  official  as  well  as  its  mi.xture  with  citric  acid 
(50';,     each),    the     "citrated"     laffein,    guaranine, 


DERIVATIVES    OK    PYRROL.  535 

koldii'uic  and  theobromine.  The  salicylate  of  theo- 
bromine is  employed  as  a  diuretic  under  the  name 
of  Diuretin. 

DERIVATIVES  OF  PYRROL,  C,H,:NH;   pyrrol 
is   found   in   bone   oil   (Dippel's  oil)  together  with 

HC— CH 

II      II 
pyridin.     It  has  the  structural  formula,  HC     CH: 


NH 
lodol,   C^I^NH,  is  produced  by  acting  with  iodin 
and  caustic  potash  on  pyrrol.      It  is  a  brown,  odor- 
less powder  containing  about  89%  of  iodin,  and  used 
as  a  substitute  for  iodoform. 

Pyrazol,  CgH^No,    has   been   obtained   artificially 
from     hvdrazin    and    chlorhvdrin.     Its    structural 
CH— CH 

II         II 
formula    is  N        CH  and  the  melting-point,  70°  C. 


NH. 
Antipyrin,  Ci^HjjNjO,  phenazone,  is  an  artificial 
alkaloid  made  from  phenylhydrazin  and  aceto  acetic 
ester.  By  heating  these,  condensation  occurs  and  a 
ketone,  phenylmethyl  pyrazolone,  is  formed.  This 
ketone,  heated  with  methyl  iodid  and  potassium 
CH3.C  =  CH 

hvdroxid,  yields  antipvrin,  CH3.N     CO         ,  soluble 

\/ 
N-CeH, 

antipyrin,  melting- 
point,  113°  C. 

and  a  very  incompatible  febrifuge. 


536  I'HARMACEUTIC   CHEMISTRY. 

DEFINITION  AND  DISCUSSION. 

The  alkaloids  may  be  considered  as  basic 
carbonaceous  amins  which  combine  with  acids 
similarly  to  ammonia  to  form  crystalline  salts. 
There  are  vegetable  alkaloids,  like  morphine;  animal, 
as  ptomain,  and  artificial  alkaloids,  as  quinolin. 
They  are  the  most  powerful  of  the  organic  principles. 
They  all  contain,  in  addition  to  nitrogen,  C  and  H 
and,  with  few  exceptions,  O.  When  heated  with 
alkalis,  ammonia  is  given  off  (distinction  from 
glucosids).  Alkaloids  are  usually  named  after  the 
generic  name  of  the  drug.  The  suffix  "ine"  (Latin, 
"ina")  distinguishes  them  from  glucosids  and  other 
principles.  Some  alkaloids,  like  morphine,  which 
has  been  named  in  honor  of  Morpheus  (the  god  of 
sleep),  and  the  alkaloids  of  the  cinchonas  are 
named  arbitrarily;  thus,  pelletierine  has  been  named 
after  the  discoverer,  etc.  They  may  be  divided  into 
amins  and  amids;  the  amids  containing  oxygen, 
the  amins  not  containing  it.  The  amins  are  liquid 
and  volatile  alkaloids  and  embrace  coniine,  sparteine, 
nicotine,  lobeline,  while  all  the  amids-are  solid  bodies. 
They  are  all  insoluble  in  water,  but  soluble  in  alcohol, 
chloroform,  benzin,  benzol,  amylic  alcohol,  kerosene, 
and  some  in  ether.  They  do  not  exist  naturally  in 
the  free  state,  but  as  acids  or  neutral  salts  comb'ned 
with  some  acids  peculiar  to  the  plants;  thus,  as 
quinine  and  cinchonine,  combined  with  the  kinic  acid 
peculiar  to  cinchona.  The  opium  alkaloids  are 
combined  with  meconic  acid,  as  meconates  and  the 


EXTRACTION    OF   ALKALOIDS.  537 

strychnos  alkaloids  of  mix  vomica,  etc.,  combined 
with  igasuric  acid,  while  other  alkaloids  are  com- 
bined with  such  common  acids  as  tannic,  citric, 
tartaric,  etc.  Alkaloidal  salts:  when  forming  salts, 
the  alkaloids  do  not  replace  the  hydrogen  of  acids, 
thus  showing  the  terms  "sulfate,"  "chlorid,"  etc., 
to  be  incorrect  when  applied  to  an  alkaloidal  salt. 
They  should  be  named  "hydrosulfate,"  "hydro- 
chlorid,"  respectively,  etc.  Ammonia  hydrochlorid 
(ammonium  chlorid)  may  serve  as  a  type  of  the 
formation  of  alkaloidal  salts;  thus: 

NH3  +  HCl  =  NH3.HCI  or  NH.Cl. 
Q7H19NO3  +  HCl  =  Ci^H^gNOa.HCl. 

GENERAL   METHODS   OF   EXTRACTION.— (i) 

When  the  native  alkaloidal  salt  is  soluble  in  water 
and  the  alkaloid  itself  insoluble,  strong  alkali  is 
added  to  a  decoction  of  the  vegetable  substance.  It 
neutralizes  the  organic  acid  with  which  the  alkaloid 
is  associated,  precipitating  the  alkaloid  in  an  impure 
state.  (2)  When  the  native  alkaloidal  salt  is 
insoluble  in  water,  a  very  dilute  acid  is  used  in  the 
extraction  of  the  drug,  so  that  it  combines  with  an 
inorganic  acid  to  form  a  salt.  This  solution  is 
decomposed  with  an  alkali,  yielding  the  alkaloid  as  a 
precipitated  salt.  The  process  may  be  divided  into 
six  steps;  thus:  (i)  Solution;  (2)  precipitation; 
(3)  re-solution;  (4)  decolorization  (with  animal 
charcoal  or  lime) ;  (5)  purification;  (6)  crystallization. 
The  salts  of  the  alkaloids  are  soluble  in  water,  some 


538  PHARMACEUTIC    CHEMISTRY. 

arc  very  freely  soluble  in  alcohol,  l)Ut  most  of  them 
are  insoluble  in  ether  and  chloroform. 

Tests. — (i)  Phosphomolybdic  acid  (Sonnenschein's 
Reagent)  produces  yellow  precipitate.  (2)  Nitric 
and  sulfuric  acids  color  many  alkaloids  reddish. 
(3)  Sodium  phosphotungstate  (Schieblcr's)  produces 
precipitates  soluble  only  in  HjPO^.  (4)  Potas- 
sium mercuric  iodid  (Mayer's)  forms  yellowish  pre- 
cipitates insoluble  in  acidulated  aqueous  solutions. 
(5)  Cadmium  potassium  iodids  (Marme's)  gives  a 
gelatinous  precipitate.  Other  alkaloidal  precipi- 
tants  are  picric  acid  and  the  following  chlorids: 
Hg,  Pt,  Au,  Sn,  lead  acetate  and  subacetate,  Lugol's 
solution,  KI  and  the  iodids  of  Hg,  Bi  and  Zn.  With 
tannin  insoluble  tannates  are  formed  (antidote). 

Among  the  unofficial  alkaloids,  aspidospermine, 
from  quebracho  bark;  berberine,  from  berberis  and 
hvdrastis;  coniine,  from  conium  seed;  delphinine, 
from  staphisagria;  emetine  and  ccpha^line  from 
ipecac;  gelsemine,  from  yellow  jasmine,  and  jervine 
and  veratralbine,  from  veratrum  (white  and  green), 
may  be  mentioned. 

THE  ANIMAL  ALKALOIDS,  PTOMAINS  AND 
LEUKOMAINS.— The  i)tomains,  as  the  cadaveric 
alkaloids  are  called,  were  so  named  by  Selmi  in  1870. 
This  authority  demonstrated  that  such  changes 
as  putrefaction,  fermentation,  etc.,  of  the  albuminous 
bodies  are  productive  of  alkaU)id-like  bodies;  that 
these  may  be  either  liquid  or  solid,  volatile  or 
fixed. 

PTOMAINS  are  formed  bv  the  ])utrefactive  changes 


05     % 


a 

05 

.rio  .TV       « 

O    0    0 

fe  o 

NNONOiNMiNOOOO         oooo 

oooooooooooo       oooo 

O  o  o 

cJ 

nm^^iUH  l,!li' 

M^    ^% 

Ji' 

"?;£<- S.oSoovo^'S^      ^    -t" 

°,ss 

w 

u-,^-1  H^ 

^ 

^-s^sss-Sf-^s    ¥^|f 

=  5-5 

^; 

OO^                                OcoNii-.                    ^„ 

o 

t^«^00    "    ^t^^OO    ro  lO  t^     ■          TfOO    „    ro 

i$ 

VO 

o         ^o^    o    o         '^.o 

c 

ffiO         gffiffi     w     5?            ffiffi 

w 

"3 

q5°„qqq§^"dgdo'  ddgo 

+ 

6 
"2:0 

S 

K.§ 

3 

-^ffi 

fflKlfflffiffiW^^Iffi^IffiK     WK^^ 

ffi^.W 

J^uuJuBy,uy.uc5    6u5icj 

u^o 

6"  S"               1    '^ 

oj 

ll  .1    1  1 

1? 

5  a  o  o  ■>.-5  «      3-0  -S  „>          ^-c 

c  c  d 

13 

rt  «  fj  «  M  » "S  -S  .S  .£  .£  .S  &  .  rt  «  S 

O 

•s  -a  -s  -s  d  c  -g  ^  e^  e-  e^  &  i  3  :§  ^  1 

3  "3  3  "3  "3  3  .S  .S  o  °  o  °  a^  o  0  o 
CCO'O'O'O'U U ^  ^  ^  ^  <;     UUU 

J3  ^  J3 

■SplOlWllB 

1       -spioiBJii^  BUoqDuiQ       -spioiBJip  umido 

BOtlUOA 

xnN 

5^ 

??1?     o'o'g'           £-..J_5  5._ 

8   8   8         O   O   O                   IT'S   o'  o'  lo  0   o'  o   o   o   o   o 

6  6  6      do  6              ^,66666666666 

IS 

_o 

u 

:i|  ::kI      M-»MI»y  = 

S 

ill  III        3s"J?s|ii?=Jl 

< 

fe 
rt 
^ 

o^<«u.  ---     g^o^cssfc":?^'^ 

o^oo  666  ^-6666666^-^9.9.^. 
^  z^z^    ^^^^  z^     5  -0  z  ^^^  z  'z'z  ;s  ^„  ^^  ^  z  :z 

ffi  ^r-^I    4 K  W     1  J.e'j:  K  K  ffi  K  E  %X  X  X  X 

u^y-    666    o    6666666^6666 

O 

.\tropina, 
Atropine  sulphas, 
Hyoscyaminae  sulphas, 
Hyoscyaminas  hydrobromi- 
dum, 
Hyoscina;  hydrobromidum, 
Homatropinae  hydrobromidum 
Scopolaminae     hydrobromi- 
dum. 

Aconitina, 

Caffeina, 

Cocaina, 

Cocaina;  hydrochloridum, 

Colchicina, 

Hydrastina, 

HydrastininjE  hydrochloridum 

Physostigmin;e  sulphas, 

Physostigminse  salicylas, 

Pilocarpin;e  hydrochloridum, 

Pilocarf)in;e  nitras, 

Sparteine  sulphas. 

•SplOIE>llB  OIlBUpXl^ 

I'TOMAINS,    LEUKOMAINS   AND    TOXINS.  54T 

of  the  animal  tissues,  and  may  be  harmless  or  poison- 
ous. Among  the  nonoxygenaled  liquid  ptoniains, 
the  following  are  monamins:  dimethylamin,  tri- 
ethylamin  and  propylamin.  Among  the  diamins: 
tetra-methylene-diamin  {putrescin),  C^HjjN,;  penta- 
methylene-diamin  (cadaverin),  C5H14N2,  and  its 
isomer  found  in  decomposing  flesh — neuridin. 

Hydrocollidin,  CuHjjN,  is  found  in  decomposing 
horse-flesh. 

Collidin,  CgHjjN  (trimethyl-pyridin),  and  the 
tetramethyl-pyridin  (parvolin),  C9H13N,  are  also 
important. 

The  oxygenated  ptomains  of  importance,  besides 
the  already-described  neiirin  and  choMn,  are: 

Gadinin,  CyHjgNOj,  found  in  putrid  fish;  niyli- 
toxin  CgHj.NOj,  found  in  poisonous  mussels. 
Gautier  (1880)  announced  that  in  the  animal  excreta 
poisonous  alkaloids  are  found,  and  he  named  these 
"leukomains." 

LEUKOMAINS  are  basic  substances  formed  by 
the  retrograde  metamorphosis  in  the  human  body. 
Leukomains  include  the  xanthin  bases;  some  are 
poisonous,  some  not. 

TOXINS  are  classed  as  ptomains,  formed  by  the 
action  of  the  pathogenic  bacteria  in  the  living 
body. 

The  combined  action  of  the  above  three  classes  of 
products  has  a  deleterious  effect  on  the  human  body, 
known  as  autointoxication.  Autointoxication,  there- 
fore, is  due  to  the  incomplete  oxidation  and  excretion 
of  these  accumulated  products  in  the  system. 


542  PHARMACEUTIC   CHEMISTRY. 

ANTITOXINS  are  bodies  found  in  the  blood- 
serum,  which  have  been  developed  there  by  the 
action  of  certain  microorganisms  in  the  body.  They 
have  the  property  of  protecting  the  animal  system 
against  further  infection  by  the  same  organism. 
This  protection  is  known  as  immunity. 

THE  PROTEINS. 

The  proteins  form  the  chief  and  constant  organic 
constituents  of  the  animal  and,  to  a  certain  extent, 
plant  bodies. 

Their  composition  is  very  complex  and  their 
structure  unknown;  they  all  contain  carbon,  oxygen, 
hydrogen,  nitrogen,  sulfur  and  phosphorus,  and 
some  contain  iron. 

Proteins  are  amorphous,  nonvolatile,  nondiffusible, 
odorless,  colorless  and  tasteless  bodies.  On  destruc- 
tive distillation,  they  yield  ammoniacal  derivatives. 

When  warmed  with  nitric  acid,  their  aqueous 
solutions  are  colored  yellow  (xanthoproteic  reaction); 
heated  with  mercuric  nitrate  in  a  solution  of  nitric 
acid,  proteins  turn  red  {Millon's  reaction) ;  boiled  with 
sodium  hydroxid  solutions,  upon  the  addition  of  a 
little  cupric  sulfate  solution,  proteins  give  violet-pink 
color  [Biuret  reaction);  boiled  Ti'///;  glacial  acetic  acid, 
and  undcrlaycd  with  strong  H^SO^,  proteins  give  a 
purple  color  at  line  of  contact  (Adamkiew-icz's 
reaction). 

Gelatin  and  peptone  are  examples  of  the  proteins. 
Thev  arc  all  distinguished  by  the  ease  with  which 
tlicy  undergo  putrefaction. 


PUTREFACTION. 


543 


PUTREFACTION. 

Putrefaction  is  a  fermentative  change  taking  place 
in  nitrogenous  substances: 
Example  (Meeker): 


Enzymes 


Peptones 


Nitrogenous  products 

Basic                   Acidic 

Indol                  i  Leucin 
Skatol                   Tyrosin 
Ptomains             Nitrous  acid. 
Ammonia,  etc.            etc.. 

Non-nitrogenous  products 


Oxalic,  lactic,  butyric, 
phenylacetic  and  phenyl- 
propionic  acids,  phenols, 
hydrogen  sulfid,  hydrogen, 
methane,  carbon  dioxid, 
etc. 


Becoming  finally,  under  sufficiently  long-continued  aerobic 
conditions: 


Carbon  Water 

dioxid  I 


Nitri 
acid 


Nitrogen 


35 


CHAPTER  XXXVIII. 

THE  TERPENES  AND  ESSENTIAL  OILS. 

The  terpenes  arc  volatile  proximate  princii)les 
of  plants.  Common  oil  of  turpentine  is  the  common- 
est type  of  the  terpenes.  Terpenes  are  hydrocarbons 
having  an  empiric  formula,  (CsHg)^.  The  following 
groups  of  terpenes  are  distinguished: 

1.  Hemiter penes,  C^Hg.  Example:  isoprene  in 
rubber. 

2.  Terpenes,  C,oHig.  E.xample:  australcne  in 
turpentine  oil. 

3.  Sesquiterpenes,  C^^^.^.  Examples:  cadinene 
and  anbebin. 

4.  Diter penes,  C^ffH^^.  Example:  Colo pliene — oxy- 
genated turpentine. 

5.  Polyterpenes,{Cioli^^)^.  Exam\)\es: caoufchouc 
and  gutta-percha. 

The  terpenes  are  further  subdivided  into  three 
classes,  according  to  physical  and  chemiial  })rop- 
erties. 

(i)  PINENE  CLASS.— This  class  embraces  the 
colorless  terpenes,  having  agreeable  odors,  boiling 
about  156°,  and  having  specific  gravities  about  0.8. 
They  are  usually  optically  active;  when  treated  with 
dry  hydrochloric,  hydrobromic  or  hydriodic  acid, 
they  add  on  one  molecule  of  these  acids.  Thus  is 
obtained  pinene  hydrochlorid,  CjoHjg.HCl,  known 
544 


LIMONENE    CLASS.  545 

as  "artificial  camphor."  With  bromin  they  form 
dibromids,  and  with  nitrosyl  chlorid,  crystalline 
compounds;  with  iodin  and  sulfuric  acid,  pinene  is 
converted  into  cymene. 

It  occurs  in  varying  quantities  in  many  essential 
oils;  the  dextro-modification,  australene,  is  found 
in  the  American  turpentine  (Pinus  australis), 
while  the  levo-modification,  lerebenthene,  is  found 
in  the  French  turpentine  (Pinus  maritima).  It 
boils  at  155°  C,  and  has  the  specific  gravity  0.855, 
and  is  obtained  by  distilling  turpentine  resin  (gum) 
with  steam. 

Turpentine  oil  (Oleum  terebinthinae)  is  employed 
in  the  manufacture  of  paints  and  varnishes.  It 
absorbs  oxygen,  in  time  becoming  resinified.  It 
fulminates  when  mixed  with  iodin. 

(2)  LIMONENE  CLASS.— Members  of  this  group 
are  also  colorless,  very  aromatic  liquids,  boiling  at 
about  170°,  having  the  specific  gravity  0.8.  These 
combine  with  two  molecules  of  dry  hydrochloric-acid 
gas,  forming  dihydrochlorids,  while  with  bromin 
they  form  crystalline  tetrahromids.  Oil  of  lemon 
peel  and  phellandrene,  occurring  in  certain  eucalyptus 
oils,  lime  and  citron  oils,  are  types  of  the  limonenes. 
They  are  optically  active.  Limonene  is  also  called 
citrene,  carvene  and  hesperidene.  Both  the  pinenes 
and  limonenes  are  cyclic  compounds : 


546  PHARMACEUTIC   CHEMISTRY. 

CH, 

I     ■ 
C 

-/\ 
HC      CH^ 

I        I 
HX      CH^ 


CH 

I 
C 

/% 
CH3  CH, 

limonene. 

(3)  MYRCENE  CLASS.— But  few  of  the  myrcenes 
known.  The  chief  difference  between  this  and  the 
above  two  classes  lies  in  the  fact  that  the  myrcenes  are 
unsaturated,  open-chain  hydrocarbons, 

=  C^^S=^^)CH.CH,.CH:C.CH, 

CH:CH, 


myrcene. 

Myrcene  is  a  constituent  of  bay  oil,  which  is  the  class 
representative. 

Dipentene  is  the  racemic  (inactive)  form  of  the 
pinenes.  It  is  found  in  many  essential  oils  and  in 
turpentine,  and  can  be  made  by  mixing  equal  parts  of 
the  two  active  limonenes. 

SESQUITERPENES,  C^^^^„  are  the  higher  poly- 
mers of  hemiterpenes  and  constitute  an  interesting 
group  of  terpenes.  In  that,  some  are  cyclic  and 
others  not,  some  form  additive  products  with  HCl 
gas,   others   will    not.     Cadiitnic.   from   oil   of  cade; 


TERPIN    HYDRATK   AND    C'AMPHKNK.  547 

humulene,  from  hop  oil,  constitute  the  reactive  ex- 
amples of  the  group,  while  clovene  and  caryophyllene, 
both  from  clove  oil,  are  nonreactive  examples. 

When  oil  of  turpentine  is  exposed  to  the  action 
of  the  air  in  the  presence  of  alcohol  and  nitric  acid,  a 
crystalline  compound,  known  as  terpin  hydralc, 
CioHi8(OH)2,H20  (terpini  hydras  U.  S.  P.),  de- 
posits through  the  union  of  three  molecules  of  water. 
It  occurs  in  rhombic  prisms,  melting  at  1 16°  C.  Ter- 
pene  hydrate,  upon  boiling  with  dilute  sulfuric  acid, 
loses  two  molecules  of  water  and  is  converted  into 
terpineol,  C,oHj7,OH,  known  as  synthetic  lilac  or 
syringa  oil,  extensively  used  in  perfumery.  Allowed 
to  stand  24  hours  in  contact  with  sulfuric  acid, 
turpentine  becomes  converted  into  terebene  (tere- 
benum  U.  S.  P.).  Terebene  is  an  optically  inactive 
mixture  of  dipentene,  terpinene,  cymene  and  cam- 
phene.     It  boils,  when  pure,  at  170°  to  185°  C. 

Terpinene  is  an  isomer  of  limonene,  and  so  is  ter- 
pinolene. 

Camphene  can  be  obtained  by  saponification  of 
pinene  hydrochlorid.  Camphene  is  a  crystalline 
body  melting  at  49°  C.  When  turpentine  is  sub- 
jected to  distillation,  the  volatile  portion  which  passes 
over  with  steam  constitutes  the  turpentine  oil,  while 
the  transparent  amber-colored  residue  constitutes 
colophony  or  "rosin."  This  rosin  consists  mainly  of 
a  complex  acid  which  is  a  derivative  of  phenanthrene, 
and  called  abietic  acid,  C18H27COOH.  It  melts  at 
146°  C,  dissolves  entirely  in  caustic  alkalis,  con- 
stituting the  "rosin  soap"  of  commerce. 


548  PHARMACEUTIC    CHEMISTRY. 

POLYTERPENES,  (CioHi6)n-  These  can  be  ob- 
tained by  polymerizing  turpentine  oil  with  antimonyl 
chlorid.  The  most  important  are  the  class  of 
rubbers. 

CAOUTCHOUC  is  contained  in  the  sap  of  the 
India-rubber  tree,  (Hevea  elastica).  This  milky  sap 
hardens  on  exposure  and  constitutes  "India  rubber," 
specific  gravity,  o.q6.  It  vulcanizes  with  sulfur 
chlorid,  constituting  "vulcanite,"  ebonite,  used  for 
many  useful  purposes.  The  best  variety  of  raout- 
chouc  is  para  rubber  (elastica  U.  S.  P.). 

GUTTA-PERCHA.— The  coagulated  milky  juice 
of  dichopsis  trees  (Isonandra  gutta).  Specific  gravity, 
0.98.  It  is  decomposed  on  melting.  Nonelastic 
below  60°,  but  very  soft  at  100°  C.  It  is  soluble  in 
benzol,  chloroform,  turpentine  and  carbon  disulfid, 
with  which  it  forms  the  rubber  cement. 

Batata  and  chicle  gums  resemble  gutta-percha 
closely. 

OXYGENATED  CONSTITUENTS  OF  THE 
ESSENTIAL  OILS. 

While  the  various  terpcnes  usually  constitute  the 
bulk  (body)  of  the  essential  oils,  their  odors  are  due 
to  some  of  the  oxygenated  carbon  compounds,  namely: 

Alcohols:  Borneol,  linalool,  geraniol,  citronellol, 
santalol,  menthol,  cincol. 

Esters:  Hornyl  acetate  and  otlior  borneol  esters; 
linalool  esters,  like  the  acetate;  geraniol  esters,  like 
the  acetate;  methyl  esters,  like  the  salicylate. 


CAMPHOR,  BORNEOL  AND  MENTHOL.     549 

Aldehyds:  Citral  (geranial),  citronellal;  benzoic 
and  cinnamic. 

Ketones:  Menthone;  carvone,  methyl  nonyl  ketone 
and  camphor. 

Phenols  :  Thymol,  eugenol,  carvacrol. 

CAMPHOR,  CioHjgO,  is  obtained  by  boiling  chips 
of  wood  from  the  camphor-tree  (Cinnamomum  cam- 
phora)  in  a  vessel  with  a  perforated  dome  into  which 
the  camphor  sublimes.  Camphor  (camphora  U.  S.  P.) 
is  defined  as  the  dextrogyrate  modification  of  the 
saturated  ketone  obtained  by  sublimation  from 
camphor  wood  Cinnamomum  c.  It  has  a  charac- 
teristic odor,  cooling  taste  and  melts  at  175°  C. 
The  melting-point  constituting  the  safest  test  for  its 
identity  and  purity. 

BORNEOL,  CioHi7(OH),  Borneo  camphor,  is 
found  in  all  three  modifications — dextro,  levo  and 
inactive.  The  common  Borneo  camphor  is  dextro- 
gyrate, melting  at  203°  and  obtained  from  the  wood 
of  Dryobalanops  camphora. 

MENTHOL,  CioHi9(OH),  mint  camphor,  is  ob- 
tained from  oil  of  peppermint  (Mentha  piperita) 
by  chilling  it.  It  is  a  secondary  alcohol  and  yields 
menthone,  a  ketone  on  oxidation.  Chemically,  it  is 
k  ex  a  h  ydroxycy  mene : 

DISCUSSION  AND  DESCRIPTION.— The  essen- 
tial or  "volatile"  oils  have  been  so  named  after  two 
facts:  because  they  are  "the  essential  odorous  prin- 
ciples of  plants  "and  because  "they  leave  transient 
or  volatile  stains  on  paper,"  this  distinguishing  them 


550  PHARMACEUTIC    CHEMISTRY. 

from   the   fats.     The   essential   oils  differ   from   the 
n.xed  oils  in  the  following  points: 

(i)  In  chemical  composition:  they  are  chiefly 
terpenes,  and  not  esters  of  the  fatty  acids. 

(2)  They  range  in  boiling-points  from  150  to  250° 
C,  volatilizing  without  decomposition. 

(3)  In  their  specific  gravities  they  range  from 
0.83  to  1. 187. 

(4)  Thev  do  not  form  soaps  with  the  alkalis. 

(5)  They  are  slightly  soluble  in  water  and  in 
definite  proportions  of  alcohol.  They  are  also  freely 
soluble  in  the  organic  solvents.  Many  of  the  volatile 
oils,  in  addition  to  C,  H  and  O,  contain  also  nitrogen; 
some  contain  also  sulfur.  According  to  these  con- 
stituents, oils  are  frequently  classified  for  pharma- 
ceutic purposes  into : 

(i)  Terpenes,  like  the  oils  of  lemon,  orange,  neroli, 
bergamot,  etc. 

(2)  Oxygenated,  like  the  oils  of  anise,  cinnamon, 
clove,  wintergreen,  rose,  etc. 

(3)  Nitrogenated,  like  the  oflicial  oil  of  bitter 
almonds,  peach  kernels,  etc. 

(4)  Suljurated,  like  the  volatile  oil  of  mustard, 
garlic,  asafetida,  horseradish,  etc. 

They  fulminate  with  iodin;  react  powerfully  v/ith 
nitric  and  sulfuric  acids;  are  readily  oxidized  by  the 
air,  acquiring  color,  resinifying,  etc.,  and  should  be 
preserved  in  cool,  dark  place,  ])referably  in  small 
comjiletely  filled  bottles. 

Adulteration. — Volatile  oils  are  frequently  adulter- 
ated with  alcohol,  which  is  detected  by  turning  milky 


ELEOPTENES.  551 

U'iih  water  on  agitation  and  b\-  dissolving  red  anilin, 
which  is  insoluble  in  the  oils.  Fixed  oils  are  detected 
by  leaving  a  permanent  stain  on  paper.  Cheaper 
volatile  oils  can  only  be  detected  by  the  specific  gravi- 
ties, by  the  optical  rotation  and  more  frequently  by  the 
sense  of  smell.  Many  of  the  oxygenated  oils  are 
mixtures  of  liquid  and  solid  principles;  the  former 
being  solvents  for  the  latter.  These  liqiiid  prin- 
ciples are  termed  eleoptenes;  the  solid  principles, 
stearoptenes  or  camphors.  Thus,  menthol  is  the 
stearoptene  or  camphor  of  peppermint  oil.  Thymol 
and  camphor  are  both  stearoptenes;  these  congeal 
upon  chilling  the  oil  and  can  be  separated  from  the 
eleoptenes. 

SAFROL,  C10H10O2  (safrolum  U.  S.  P.),  the 
methylene  ether  of  pyrocatechol  found  in  sassafras 
and  camphor  oils,  is  a  type  of  the  eleoptenes. 

EUGENOL,  QoHj^O,  U.  S.  P.,  is  an  unsaturated 
aromatic  phenol  found  in  clove  and  pimenta  oils. 

EUCALYPTOL,  C,^Yi,^0  (cirfeol),  is  an  inactive 
organic  oxid,  boiling  at  176°  C;  specific  gravity, 
0.93. 

CAMPHORA  MONOBROMATA,  CioH^^BrO,  the 
monobromated  camphor  of  pharmacy,  is  a  substitu- 
tion product  of  camphor  and  bromin.  It  is  insoluble 
in  water,  soluble  in  other  solvents,  and  used  as  a 
sedative. 


552 


PHARMACEUTIC    CHEMISTRY. 


Structures: 
CH, CH- 


-CH       CH, 


-CH- 


-CH„ 


H3C— C— CH 

I 
CH..-^ C CH      CH. 

I 

CH3 

camphene,  CioHie 


H3C— C— CH3 


CH(OH) 


CH3 


CH, 


-CH- 


borneol.  CioHit.OH 
-CH3 


HX— C— CH, 


CH, 


-c  =  o 


I 
CH3 


camphor,  C9H16.CO 

PREPARATION  OF  VOLATILE  OILS.— Volatile 

oils  are  prepared  after  t)nc  of  the  five  methods  fol- 
lowing: 

(i)  By  distillation  ivith  steam;  thus,  the  oils  of 
peppermint,  spearmint  and  rose  are  distilled  from  the 
coarsely  comminuted  drugs.  The  oils  floating  on  top 
are  separated.  The  condensed  waters  are  sold  as 
distilled  "floral  waters."  (2)  By  expression;  where 
the  oil  is  readily  separated,  as  in  the  case  of  the  oils 
of  orange,  lemon  and  bergamot  peel. 

(3)  By  extraction  with  solvents;  in  cases  where  the 
delicate  oils  would  decompose  with  heat,  they  are 
extracted  by  macerating  the  flowers  with  odorless 
fi.xed  oils  or  lard  (enfleurage)  from  these  they  are 
dissolved  out  by  alcohol   which   is  distilled  off'  in 


PREPARATION   OF    VOLATILE    OILS.  553 

vacuum.    Oils  of  jasmin,  tuberose,  etc.,  are  obtained 
thus. 

(4)  By  distillation  of  oleoresins;  thus,  the  oils  of 
turpentine  and  copaiba  are  obtained. 

(5)  By  destructive  dist illation  are  obtained  the  oils 
of  tar  and  cade,  from  pine  and  juniper-wood,  respect- 
ively. 


2i2 
1' 

S% ;  hydrocyanic  acid, 
1  2,  Mor  more  than  4%- 
laO;    anisic    aldehyd, 
sic  acid;  methyl  chari- 

0i  U  il 

§  Ml 

-1^ 

b|5 

•3 

•50 

1  IMpi^ 

li 

iiaiiciwPiSs 

mummmmimi 

b 

cq    ^       -        -              ._        ^         ^     . 

J 

J             J       H 

0     C)          O^iJ 

^ 

Uo> 

0 

to               U       . 

■*  t30 

vO 

in  OS                   \C    0        I^ 

^ 

°    °    ? 

0000             0000      - 

o>          00 

w 

M     M     0 

0 

00              00-' 

d         d  M 

^1 

II 

lis 

PI 

2„ 

Is 

1      1.  H 
1      li  g^ 

^'     1     ■    11 
-OS          =s 

rt'^M 

le 

■^         |e    1^1 

>.    "-^        '^'^ 

e§^ 

s 

;g            E       grt 

■S   -1      l^s  . 

I-"  -i 

d 

v^ 

J, 

ol      S 

>> 

«  f^ 

0 

> 

c 

C       S 

w 

■c             .2 

"m      C-                 ? 

II 

J 

1    1 

It      s 

8    .2,          ^ 

1 

ii 

1 

11 

1      1 

li  li 

p 

1    ft 

IJ  W 

O 

s 

f 

1 

*j      > 

3 

"S 

s 

^  I     -i 

«  3    ^^ 

ll 

0, 

1    ■         1 

(3                                  w 

1  -s     1^ 

"So        2I 

1 

8 

2                      "S 
1              ^0 

13  k 

2 

IP 
til 

■5 

11 

1     i 

2      %   ^ 

n  If 

eSs 

SS 

0      •"    - 

E     E        EE 

a--  3 

a  c 

0                      0             3 

33        33 

V.O  0) 

(U   <3 

a                     a           ii 

O    O 

0 

0                     00 

5   5      55 

m 


111 


^    K 


c    ^6 


-^  c 


•S'^o 


11       ,: 


^b^*^  i 


SS 


"►thsSm     o.oJii'SS^^  -g-c  e»;^0-^  g^^  ::c  3.Hgd„■ 


Oi-lQ     H     O 


a>      >.  o-g  00  00  00  !> 
o     O  ►-O  o  o  o  o 


^2 
I 

u 


.5  <u 

j20 


o         — 

;^  1^ 

111"? 

S&S  Eo 
o   o 


Pi 

111 


£0) 


ooo    o    o 


p 
i 

111 
III 

o 

Linalyl  acetate,  C12H20O2  (about  8% 
in  the  English  and  25  to  38%  in 
the  French  oils) ;  pinene  and  limo- 
nene, CioHie;  geraniol  and  cineol, 

Citral,  4%,  CioHibO;  limonene  and 
phellandrene,  CioHie;  citronellal, 
CioHisO;  linalyl  and  geranyl 
acetates,  C12H20O2. 

Menthol.  50%  (wt.),  CioHi<..OH; 
menthyl  acetate,  C12H22O2;  limo- 
nene, phellandrene,  CioHie  acet- 
aldehyd  and  amylalcohol. 

Carvone,  CaHu.CO;  limonene,  pin- 
ene. CioHiB. 

Myrcene.  CioHib;  eugenol,  CioHi-O:; 
methyl  eugenol,  CiiHuO-;  phel- 
landrene, CioHie;  citral,  CioHibO. 

Pinene,  CioHis;  myristicol,  CioHi.s.- 
OH;   myristicin.   C12HMO2. 

Pinene.  CioHic;  cresols.  C6H4(OH)- 
CH,,. 

Eugenol.  6s%  (vol.).  C!oH,202; 
caryophvllene,  CuH24. 

Geraniol,  CioHis.OH;  citronellol, 
C10H17.OH.  and  some  aromatic 
hydrocarbons  and  alcohols. 

o 

0                                    00 
00                    00                Ov               S      0            Ov      S 
0                 0              0              d      M          0      0 

M            0 

Is 

p 
.2 

1 

stillation 

echanical 
means 

stillation 

stillation 
stillation 

stillation 
stillation 

P            P 

.2     .2 
1     1 

■a               B           -a           Ti     13        -r     -c 

•0     -o 

' 

> 

a 
o 

d 

fresh  flowers  (Lavendula  vera) 

fresh  peel  (Citrus  limonum) 

leaves  of  tops  (Mentha  piperita) 

leaves  and  tops  (Mentha  viridis) 
leaves   (Myrcia  acris) 

seed  (Myristica  fragrans) 
oleo  resin  (Pix  liquida) 

p 

p   i 

a    -o 

.2     S 
e      0 

1    ^ 

II 

2: 

1 
P 

"S 
O 

Oleum    lavendute    florum    (oil    of 
lavender  flowers) 

Oleum  limonis  (oil  of  lemon) 

Oleum  menthse  piperita  (oil  of  pep- 
permint) 

Oleum  mentha;  viridis  (oil  of  spear- 
mint) 
Oil  of  bay 

Oleum  myristicse  (oil  of  nutmeg) 
Oleum  picis  liquidae  (oil  of  tar) 

5 

e 

a    ^ 
"o      S 

1     o- 

5  ^ 
p  ^ 

•5.  s 

-E     E 

5   0 

^s* 


OKJ    K||    ^"1   ^„ 

2      g  O-  fe  C  «  II      o 


s  <^ 


OilO 


Cfl 


20- 


u 


So  2 
S£52oqS|-3 


r-  M  O        mo 
o  o  o\     00  00  ON 
M  11  o       o  o  o 


d   I 

in     -2- 


^     E 


c 

52 

> 

■S      o 

i 

2c 

II 

r.    >. 

e 

F 

EE 

i^ 

■3      E 
E?^ 

E'«E 

3 

a  3 

Ji 

o 

o 

OO 

O 

O    O 

O    O 

CHAPTER   XXXIX. 

THE  PURIFICATION  OF  ORGANIC  COMPOUNDS. 

There  are  three  methods  used  in  the  purification 
of  organic  compounds: 

1.  Crystallization  |  .      ,  r     i-  i 

^  "   .        .  >  m  the  case  of  solids. 

2.  bul)limation      j 

3.  Distillation — in  the  case  of  liquids. 

Solvents. — In  the  case  where  solids  are  to  be  puri- 
fied by  crystallization  and  recrystallization,  deter- 
mine the  best  solvent ;  one  which  dissolves  the  most  of 
the  salt  while  hot,  and  which,  on  cooling,  crystallizes 
out  the  dissolved  salt.  Some  solvents  are  inflam- 
mable; others  are  not.  In  cases  where  inflammable 
solvents  are  used,  employ  the  steam-bath  or  water- 
bath  to  heat  the  same  and  never  the  naked  fame. 

Goggles  should  be  used  to  protect  the  eyes  while 
working  with  volatile  solvents. 

While  subliming  substances,  the  same  should  be 
mixed  with  about  an  equal  quantity  of  pure  sand 
which  has  been  heated  previously  for  about  ao 
minutes.  The  funnel  used  should  have  its  mouth 
covered  by  a  filter  paper  and  the  beak  stopped  up 
by  means  of  a  paper  plug. 

Some  substances  sublime  without  previous  lique- 
faction, other  liquefy  first.  (Try  naphthaline,  CjoHg, 
and  benzoic  acid,  CglI,.,COOH,  as  e.xamples). 

Distillations  in  vacuum  and  with  steam  arc  often 
558 


ORGANIC  ANALYSIS.  559 

employed  in  the  purification  of  liquids.  The  con- 
densed vapor  is  frequently  saturated  with  the  dis- 
solved substance  and  can  be  "salted  out"  by  satu- 
rating the  water  with  ordinary  salt,  and  "  taken  up" 
with  a  volatile  solvent  like  ether.  The  solutions  of 
solids  or  liquids  are  frequently  filtered  through  bone- 
black  before  crystallizing  or  separating  them  and  are 
thus  freed,  from  impurities. 

BEHAVIOR    OF    ORGANIC    SUBSTANCES   WITH 
IMMISCIBLE  SOLVENTS. 

Upon  agitating  the  substance  with  distilled  water 
acidulated  with  2%  of  H^SO^,  and  adding  half  its 
volume  of  an  immiscible  solvent  (ether,  chloroform,  or 
benzene),  the  following  are  extracted: 

(i)  In  the  acidulated  aqueous  liquid  there  may  be 
dissolved  carbohydrates,  soluble  alkaloidal  salts,  acids, 
organic  bases  and  proteins.  Add  a  small  excess  of 
NaOH  solution  and  half  its  volume  of  an  immiscible 
solvent  and  again  shake,  thus  further  separating  the 
above  into  (a)  and  (b). 

(a)  The  alkalin  aqueous  extract  may  contain : 
Carbohydrates,  as  dextrin,  sugars,  gums. 
Soluble  alcohols,  as  methyl,  ethyl,  propenyl. 
Soluble  acids,  as  acetic,  tartaric,  citric,  lactic, 

malic,  oxalic. 
Alkaloids  and  organic  bases,  as  urea,  curarine, 

cinchonine,  pyridine  and  morphine. 
Coloring  matters,  as  indigo,  cochineal,  cudbear. 
Proteids,  as  albumin,  casein,  gelatin. 
36 


560  PHARMACEUTIC    CHEMISTRY. 

(b)  The  immiscible  layer  may  contain: 

Vegetable  alkaloids,  as  quinine,  strychnine,  acon- 

itine,  atropine,  nicotine. 
Coal-tar  bases,  as  anilin,  chrysotoluidin,  pyridin 
and  their  homologues. 
(2)  In  the  immiscible  solvent  there  may  be  dissolved 
hydrocarbons,   oils,   acids,  coloring  matters,  resins, 
phenols  and  glucosids.    Add  water  containing  a  small 
excess   of    NaOH    and    shake    again,    thus  further 
separating  the  above  into  (a)  and  (b). 
(a)  The  alkalin  aqueous  extract  may  contain: 

Fatty  acids,  as  stearic,  oleic,  palmitic,  valeric. 
Aromatic  acids,  as  benzoic,  salicylic,  phthalic. 
Acid  coloring   matters  and  dyes,  as  picric  or 
chrysophanic  acid,  aurin,  saffranin,  alizarin 
or  bilirubin. 
Acid  resins,  as  colophony  (common  pitches). 
Phenols,  as  phenic  and  cresylic  acids,  thymol 

and  creasote. 
Glucosids,  as  santonin,  picrotoxin. 
Q))  The  immiscible  layer  may  contain: 

Hydrocarbons,  solid,  as  paraffin,  naphthalene, 

anthracene. 
Hydrocarbons,  liquid,  as  petroleum   products, 

rosin-oil,  benzene. 
Essential  oils,  as  turpentine,  tcrpcnc  and  oxy- 
genated oils. 
Nitro-compounds,  as  nitrobenzene. 
Chloroform,   also  ethers,  as  ethyl   oxid,   ^:{\^\\ 

acetate,  nitroglycerin,  etc. 
Fixed  fats,  oils  and  waxes. 


QUALITATIVE    TESTS.  56  I 

Neutral  resins  and  coloring  matters. 
Camphors,  as  laurel  camphor,  borneol,  menthol. 
Insoluble  alcohols,  as  amyl,  cetyl  and  cholesterin. 
Glucosids,  as  saponin,  santonin  and  digitalin. 
Weak  alkaloids,  as  caffeine,  narcotine,  piperine, 
colchicine. 

THE     ANALYSIS     OF     ORGANIC     COMPOUNDS. 

THE    QUALITATIVE    TESTS. 

TESTS  FOR  CARBON.— (i)  Any  organic  sub- 
stance chars;  if  it  chars,  it  is  organic.  A  few  inorganic 
compounds,  like  Cu(C2H302)2,  also  char,  while  some 
organic  substances,  as  CHCI3,  volatilize  without  first 
charring. 

(2)  Mix  an  organic  substance  with  finely  powdered 
CuO,  heat  and  convey  the  gas  into  lime-water, 
CaCOg  will  be  deposited  in  presence  of  organic 
compounds. 

TEST  FOR  HYDROGEN.— Heat  the  dry  substance 
in  a  dry  test-tube;  if  moisture  or  drops  of  H2O  collect 
in  the  upper  portion  of  the  tube,  hydrogen  is  present. 
Or,  heat  the  substance  with  CuO,  when  water  will  jorm. 

Quantitatively,  Hj  may  be  estimated  by  passing  the 
gas  formed  through  CaClj  tube  previously  weighed. 
H2  being  ^  of  the  HjO  found. 

TEST  FOR  NITROGEN.— (i)  When  organic  sub- 
stance i  heated  with  soda  lime,  which  is  a  mixture  of 
equal  parts  of  CaO  and  NaOH  (heated  together  until 
perfectly  dry),  ammonia  (NH3)  is  formed.  Heat, 
hold  a  piece  of  turmeric  paper  over  the  mouth  of  the 


562  PHARMACEUTIC    CHEMISTRY. 

tube,  and  a  brown  spot  will  form.     This  test  is  not 
universal. 

RELIABLE  TEST  FOR  NITROGEN.— (2)  A  piece 
of  metallc  sodium  (half  a  pea  size)  is  placed  in  a 
long,  narrow  test-tube  with  some  of  the  substance  to 
be  tested.  Heat  slowly,  and  carefully,  until  redness 
is  reached. 

Protect  the  eyes. 

The  C  and  the  N  will  unite  with  the  Na  to  form 
Na(CN).  Break  the  tube  in  water,  heat  the  water 
to  extract  the  cyanid,  filter  from  carbonaceous  mat- 
ter, and  add  FeS04  to  the  solution,  then  HCl  to 
acidify,  and  heat.  The  alkalin  Na(CN) -l-FeSO,= 
Fe(OH)2  which  is  precipitated,  and  sodium  ferro- 
cyanid  formed;  thus: 

6Na(CN)  +  Fe(0H)2  -  Na,Fe(CN)6  +  2NaOH 
and   on   addition  of  FeCl,  =  ferric   ferrocyanid  or 
Prussian    blue   is   formed.     (Use   dry  acetamid  or 
quinolin  for  this  test.) 

TEST  FOR  HALOGENS.— (I)  The  simplest  test  is 
to  heat  a  copper  wire  until  it  ceases  to  color  the 
llame  green.  A  small  quantity  of  an  organic  halogen 
compound  is  now  heated  on  the  end  of  the  wire  in 
the  flame,  which  in  the  presence  of  halogen  com- 
pounds will  produce  or  acquire  a  green  coloration. 
(Use  CHI3  for  a  solid  halid  and  CHCI3  for  a  liquid). 
This  test  sometimes  jails. 

(2)  Test  for  halogens  in  the  presence  oj  S  or  N. — 
Acidify  the  solution  with  dilute  HjSO^,  boil  for  5 
minutes  in  open  vessel  to  expel  the  HjS  formed  and 
the  HCN.    Filter,  acidifv  with  dilute  HNO,;  to  i  cr. 


ULTIMATE  ANALYSIS.  563 

of  the  solution  add  a  few  drops  AgNo3  solutitm.  If 
a  precipitate  forms,  acidify  a  larger  portion  with  HCl, 
add  a  few  drops  of  CSj  and  then  CI2  water  drop  by 
drop,  continuing  the  addition  if  /  is  present,  until  the 
violet  color  disappears. 

(3)  Tests  for  Halogens  in  Absence  oj  N  or  S. — This 
is  the  same  'as  above;  omit  the  treatment  with 
H2SO4  and  the  boiling  for  5  minutes. 

TESTS  FOR  PHOSPHORUS  AND  SULFUR  IN 
ORGANIC  COMPOUNDS.— Sulfur  and  phosphorus 
may  be  detected  and  estimated  by  heating  the  sub- 
stance with  nitric  acid.  This  is  done  in  a  sealed 
tube  provided  with  a  capillary  tube;  and  it  should 
be  r  membered  that  great  care  is  necessary  in  break- 
ing the  capillary  tube  open.  By  the  heating,  the 
sulfur  will  be  oxidized  entirely  to  HjSO^  and  the 
phosphorus  to  H3PO4.  These  can  be  tested  for  by 
appropriate  reagents  qualitatively  or  estimated  quan- 
titatively by  the  usual  methods. 

ELEMENTARY  ORGANIC  ANALYSIS. 

In  the  discussion  under  this  head  we  will  present, 
in  outline  only,  principles  of  chemical  analysis,  by 
means  of  which  we  may  determine  the  percentage 
composition  and  the  empiric  formulas  of  com- 
pounds containing  carbon,  hydrogen,  oxygen  and 
nitrogen,  and  al  o  suljiir  and  phosphorus. 

CARBON  AND  HYDROGEN.— These  elements 
are  determined  by  burning  the  body,  at  a  red  heat,  in 
a  "combustion  tube"  of  glass,  porcelain  or  platinum, 
with  oxygen.     Under  such  circumstances,  the  carbon 


564  I'HARMACEUTIC    CHEMISTRY. 

of  the  compound  is  hurncd  to  carbon  dioxid,  CO,; 
and  the  hydrogen  i^  burned  to  steam,  H,^.  The  gas- 
eous products,  COjand  H2O,  are  aspirated  through  a 
weighed  tube  containing  d  y  calcium  chlorid,  CaClz- 
TheH20  is  abso  bed  by  the  CaCl^and  the  increase  in 
weight  of  the  tube  is  the  weight  of  water  absorbed. 
The  CO2  is  further  aspirated  through  a  weighed  tube 
filled  with  grains  of  a  mechanical  mixture  of  sodium 
hydroxid  (NaOH)  with  lime  (CaO).  The  COj  is 
absorbed  in  this  tube,  forming  sodium  carbonate, 
NajCOj;  and  the  increase  in  weight  of  the  "soda 
lime"  tube,  is  the  weight  of  CO2  absorbed.  Having 
determined  its  weight,  we  are  now  in  a  position  to 
calculate  the  percentages  of  carbon  and  hydrogen  in 
the  body  under  examination.  We  must  first  calcu- 
late the  weights  of  carbon  and  hydrogen  from  the 
observed  weights  of  CO2  and  HjO;  thus: 

CO2  :  C  =  44  :   12. 

44  :   12    =    observed   weight   of    COj  :  required 
weight  of  C. 


18   :  2    =    oljserved   weight   of   HjO    :   required 
veight  of  H,. 


Now  calculate  percentages,  thus: 

Weight  of  carbon  determined   ^  ^^^  ^  ^^^^    ^f  ^^^,^^„ 

Weight  of  body  taken  ;„  jj^p  ^^^^y 

Weight  of  hydrogenjietermuied   y^  ^^^  ^  per  cent,  of  hvdro- 
Weight  of  body  taken  g^^  j^  ^Yie  body." 


DETERMINATION    OF    NITROGEN.  565 

NITROGEN.— This  element  is  most  conveniently 
determined  by  the  method  of  Kjeldahl.  The  princi- 
ples concerned  are  as  follows : 

I.  The  nitrogenous  body  is  vigorously  boiled  in 
concentrated  sulfuric  acid  (H2SOJ.  This  treatment 
so  operates  as  to  bring  about  the  formation  of  am- 
monium sulfate  (NH4)2S04,  which  salt  contains  all  of 
the  original  nitrogen  of  the  body  under  examination. 

II.  Solution  I  is  made  strongly  alkalin  with 
sodium  hydroxid  (NaOH)  and  then  boiled.  The 
ammonium  sulfate  is  decomposed  by  this  process 
with  the  formation  of  sodium  sulfate,  NajSO^,  and 
the  liberation  of  ammonia  gas  (NH3): 

(NH,)2SO,  +  2NaOH=  2NH3  +  2H20  +  Na2SO,. 

III.  The  NH3  liberated  from  solution  II  is  con- 
ducted into,  and  absorbed  by,  a  solution  that  contains 
a  known  weight  of  hydrochloric  acid,  HCl,  the 
HCl  being  in  excess:  NH3  +  HCl  =  NH.Cl. 

A  portion  of  the  HCl  is  thus  neutralized  by  the 
NH3. 

IV.  Solution  III  is  titred  with  a  standard  solution 
of  NaOH,  using  phenol-phthalein  or  another  efficient 
indicator.  The  excess  of  HCl  is  thus  dete  mined, 
from  which  the  quantity  of  HCl  required  to  neutralize 
the  Nftg  is  obtained  by  subtraction. 

V.  Calculate  the  HCl  equivalent  to  nitrogen  (in 
ammonia),  thus: 

HCl  :   N   =  36.5   :    14. 
36.5  :  14  =  weight  of  HCl  used  to  neutralize  the 


566  PHARMACEUTIC   CHEMISTRY. 

VI.  Calculate  the  percentage  of  nitrogen;  thus: 

Weight  of  nitrogen  determined  ^  ^^^^        ,,„t  ^f  nitrogen 
Weight  of  body  taken  ^  ^he  body. 

VOLUMETRIC  ANALYSIS.— We  have  used  the 
terms  litre  and  standard  solution  in  explaining 
Kjeldahl's  method  for  the  determination  of  nitrogen 
in  organc  bodies.  It  is  necessary  that  the  meaning 
of  these  terms  should  be  explained. 

The  principle  upon  which  volumetric  analyses  are 
based  is  this:  By  means  of  the  balance  we  prepare  a 
solution,  one  unit  volume  of  which  (usually  i  c.c.)  is 
made  to  contain  a  certain  weight  of  some  chemically 
active  substance — the  exact  substance  used  being 
dependent  upon  the  particular  analysis  we  desire  to 
make.  Such  a  known  solution,  is  called  a  standard 
or  volumetric  solution. 

A  standard  or  volumetric  solution  of  anv  chemic- 

ally  active  substance  is  called  a  normal  ~  solu- 
tion when  it  contains  in  one  liter  (looo  c.c.)  as  much 
of  the  chemically  active  substance  as  is  equivalent 
to  one  gram  of  hydrogen. 

If,  now,  in  the  course  of  an  analysis,  we  prepare 
another  solution  that  contains  an  unknown  weight  of 
some  body  that  can  enter  into  a  definite  chemical 
reaction  with  the  body  in  the  standard  solution,  the 
standard  solution  furnishes  us  with  means  for 
determining  the  actual  weight  of  active  material  in 
the  unknown  solution.  It  is  only  necessary  for  us  to 
measure  the  number  of  unit  volumes  of  the  standard 


DETERMINATION    OF    NITROGEN.  567 

solution  required  to  conclude  a  certain  reaction  with 
all  of  the  active  material  in  the  unknown  solution. 
Then,  since  each  unit  volume  of  the  standard  solution 
corresponds  or  is  equivalent  to  a  definite  weight  of  the 
active  body  in  the  unknown  solution,  it  is  simply 
necessary  to  multiply  the  number  of  unit  volumes  of 
standard  solution  used  by  the  previously  determined 
factor  which  expresses  the  weight  of  active  material 
in  the  unknown  solution  equivalent  to  one  unit 
volume  of  the  known  or  standard  solution. 

We  are,  therefore,  required  to  have  some  means 
both  for  measuring  the  volume  of  standard  solution 
used  and  for  determining  when  the  reaction  has  been 
fully  completed.  In  order  to  measure  the  volume  of 
standard  solution  employed,  we  make  use  of  a  nar- 
row, graduated  glass  cylinder,  called  a  burette.  In 
order  to  tell  the  end  point  of  our  titration,  we  make  use 
of  a  solution  of  some  body  that  is  capable  of  causing  a 
marked  color  change  with  a  minute  quantity  of  our 
standard  solution,  but  cannot  do  so  as  long  as  any  of 
the  active  material  in  the  unknown  solution  remains 
unacted  upon.  Such  a  body  is  termed  an  indicator, 
because  it  indicates  the  completion  of  the  principal 
reaction. 

Passing  from  the  above  general  exposition  of  the 
nature  of  volumetric  analyses  and  coming  to  the 
Kjeldahl  method  for  the  determination  of  nitrogen, 
we  have  to  consider  the  quantitative  relations  of  the 
reaction  between  NH3  and  HCI.  The  reaction  is 
written : 

NH3  +  HCI  =  NH.Cl. 


568  PHARMACEUTIC   CHEMISTRY. 

Therefore,  14  parts  of  nitrogen  coriespond  to  36.5 
parts  of  hydrochloric  acid. 

In  the  course  of  our  analyses  we  obtained  a  solu- 
tion that  contained  all  of  our  nitrogen  as  ammonia. 
This  would  be  our  unknown  solution — for,  while  we 
know  that  it  contains  all  of  our  nitrogen  as  am- 
monia, we  do  not  know  the  weight  present. 

Let  us  now  have  prepared  two  standard  solutions — 
one  containing  3.65  grams  of  HCl  per  litre  (=  .00365 
grams  per  c.c.) ;  and  the  other  containing  4  grams  of 
NaOH  per  liter  (  =  .004  grams  per  c.c.)  Any  given 
volume  of  either  of  these  solutions  would  be  exactly 
equivalent  to  the  same  volume   of   the  other,  thus: 

NaOH   +   HCl    =   NaCl    +   H^O. 
40  36-5 

Suppose  that  the  body  being  analyzed  weighed  5 
grams  and  that  its  nitrogen  after  being  changed  to 
ammonia  was  distilled  into  50  c.c.  of  our  standard 
HCl.  Some  of  the  HCl  would  have  been  changed 
to  neutral  NH^Cl.  Now  add  a  few  drops  of  an 
alcoholic  solution  of  phenolphthalein  (which  is 
colorless  in  the  presence  of  free  HCl,  but  is  crimson 
in  the  presence  of  free  NaOH) ;  and  then  run  into  the 
solution  from  a  burette  NaOH  solution  until  a  red 
color  appears.  Suppose  that  30  c.c.  NaOH  solution 
accomplished  this  result.  ELvidently  50  — 30  =  20  c.c. 
of  our  HCl  was  neutralized  by  the  unknown  weight 
of  NH.,.  But  as  i  c.c.  HCl  wc  know  to  be  equiva- 
lent to  .0014  gram  of  nitrogen.  Therefore,  if  our  5 
grams  of  sam])le  contained  .0014  X  20  =  .028  gram 


DETERMINATION  OF  SULFUR  AND  PHOSPHORUS.       569 

of  nitrogen.     The  percentage  of  nitrogen  is  therefore 

0.028.,  „/cO/ 

X  100  =  .56%. 

Note. — By  means  of  special  volumetric  analyses  we 
determine,  clinically,  the  quantitative  composition  of 
urines,  gastric  juice,  water,  and  drug  strength,  etc. 

DETERMINATION  OF  SULFUR  AND 
PHOSPHORUS. 

In  order  to  determine  the  percentage  of  sulfur  and 
phosphorus  in  organic  bodies,  we  heat  the  bodies  with 
strong  nitric  acid.  By  this  treatment  the  sulphur  is 
converted  to  sulfuric  acid  and  the  phosphorus  to  ortho- 
phosphoric  acid.  These  are  precipitated  separately 
(the  sulfuric  acid  by  barium  chlorid  in  the  presence 
of  hydrochloric  acid;  and  the  phosphoric  acid  by 
magnesium  chlorid  in  the  presence  of  ammonium 
hydroxid)  and  weighed,  after  ignition  in  a  plati- 
num crucible,  as  barium  sulfate  (BaSO^),  and 
magnesium  pyrophosphate  (Mg2P207),  respectively. 
The  weight  of  BaSO^  and  MgjPzO^  are  calculated  to 
S  and  Pj,  respectively;  and  thence  the  percentage  of 
sulfur  and  phosphorus  in  the  organic  body  obtained. 

Determination  of  Oxygen. — Oxygen,  being  difhcult 
to  determine  directly,  is  usually  determined  by 
difference.  We  determine  all  the  other  elements  in 
the  body,  and  subtract  the  sum  of  the  percentages 
from  100.  The  remainder  is  taken  as  being  the 
percentage  of  oxygen. 

Calculating  Empiric  Formulas. 
Having  obtained  the  percentages  of  the  various 


570  PHARMACEUTIC    CHEMISTRY. 

elements  that  enter  into  the  composition  of  tlie 
organic  body  under  examination,  we  are  in  a  position 
to  calculate  its  empiric  formula. 

By  the  empiric  formula  for  a  jjody  we  mean  the 
simplest  formula  that  shows  a  composition  in  har- 
mony with  our  elementary  analysis. 

The  method  for  calculating  empirical  formulas 
will  be  understood  from  an  inspection  of  the  sub- 
joined example.  An  elementary  analysis  of  lactic 
acid  showed  that  it  has  the  following  elementary 
composition: 

Carbon        =    40.00  per  cent. 
Hydrogen   =     6.6  per  cent. 
Oxygen       =    53.4   per  cent, 
in  100.00  parts. 

Divide  the  above  numbers  by  the  respective  atomic 
weights: 

^=3.3       ^^=6.6         -5^=3.3 
C,      H.,      O. 
The  ratio,  therefore,  is  =  S-3   •  ^-^   •  3-3  = 

or  =1:2:1 

The  carbon  and  oxygen  atoms  are,  therefore, 
equally  numerous  in  lactic  acid,  but  the  hydrogen 
atoms  are  twice  as  numerous  as  eitber  the  carbon 
atoms  or  the  oxygen  atoms.  The  simplest  formula 
for  lactic  acid  is,  therefore,  CH^O. 

UNSATISFACTORY    NATURE    OF    EMPIRIC 
FORMULAS. 

We  have  seen  above  that  the  formula  CHjO  ex- 
presses an  elementary  composition  in  entire  acco:d- 


DETERMINATION   OF    MOLECULAR    WEIGHT.      57 1 

ance  with  our  analytical  knowledge  concerning 
lactic  acid.  But  that  this  formula  is  quite  irrational 
is  evidenced  by  the  fact  that  we  know  a  number  of 
bodies  that  have  properties  widely  differing  from  the 
properties  of  lactic  acid;  but  to  which  we  would  give  an 
identical  empiric  formula.  Such  bodies  are  formalde- 
hyd,  formose,  grape-sugar,  fruit-sugar,  acetic  acid, 
etc. 

A  rational  formula  for  lactic  acid  would  show  the 
manner  in  which  lactic  acid  differs  from  the  other 
bodies  mentioned.  Now  the  formula  for  lactic  acid 
may  very  well  be  some  multiple  of  CH2O.  We  must, 
therefore,  write  (CH20)nas  theformulafor  lactic  acid. 
The  "n"  meaning  some  definite  whole  number  as 
yet  undetermined.  We  are,  therefore,  at  this  stage 
entirely  unacquainted  with  the  true  molecular  weight 
of  lactic  acid,  and  have  no  means  for  explaining 
why  its  properties  should  be  expected  to  differ  from 
those  of  certain  other  bodies  having  an  identical  per- 
centage composition. 

DETERMINATION  OF  TRUE  MOLECULAR 
WEIGHT. 

We  have  a  number  of  methods  by  means  of  which 
we  may  arrive  at  conclusions  as  to  the  molecular 
weights  of  bodies.  Two  of  these  methods  we  will 
now  discuss. 

Molecular  Weight  by  Chemical  Reasonings. — Let  us 
consider  the  well-known  compound,  water,  seeking 
to  discover  how  many  times  heavier  is  its  molecule 
than  an  atom  of  hydrogen. 


572  PHARMACEUTIC    CHEMISTRY. 

From  our  analyses  of  water,  we  know  it  to  be  com- 
posed of  hydrogen,  one  part,  and  oxygen,  eight  parts, 
by  weight.  Each  molecule  of  water,  therefore,  con- 
tains at  least  one  atom  of  hydrogen  and  one  atom  of 
oxygen.  We  might  for  the  moment  write  the  formula 
HO  (which  would  make  oxygen  have  an  atomic 
weight  of  8). 

Now,  23  parts  of  the  element  sodium  can  react  with 
18  parts  of  water,  liberating  i  part  of  hydrogen;  and 
forming  a  perfectly  definite  compound  that  contains 
all  of  the  sodium  that  was  used,  all  of  the  oxygen 
from  the  water,  and  one-half  of  the  hydrogen  from 
the  water.  It  is  a  primary  conception  that  an  atom 
cannot  be  divided;  and,  since  we  have  observed  that 
the  hydrogen  in  the  water  molecule  can  be  split  into 
two  equal  parts,  it  is  an  unavoidable  conclusion  that 
the  molecule  of  water  must  contain  at  least  two  atoms 
of  hydrogen.  We  are  consequently  in  a  position  to 
write  the  formula   H2O  for  the  molecule  of  water. 

No  experiment  has  ever  shown  that  the  hydrogen 
in  the  water  molecule  can  be  divided  into  more  than 
two  parts.  Also,  no  one  has  ever  been  able  to  divide 
the  oxygen  in  the  water  molecule.  We  have,  then, 
most  excellent  reasons  for  writing  the  formula  H^O 
as  truly  expressing  the  molecule  of  water.  But  the 
atom  of  hydrogen  is  taken  as  unity;  the  hydrogen  in 
the  water  molecule,  therefore,  weighs  two,  and, 
since  we  know  by  analysis  that  water  has  eight  times 
as  much  oxygen  as  hydrogen,  it  follows  that  the 
oxvgen  in  the  water  molecule  must  weigh  (2X8  =  16) 
sixteen.     The  molecular  weight  of  water  is,  therefore 


DETERMINATION    OF    MOLECULAR    WEIGHT.      573 

(2  +  16  =  18),  eighteen;  or,  in  other  words,  the 
molecule  of  water  weighs  eighteen  times  as  much  as 
one  atom  of  hydrogen. 

By  similar  reasonings  we  could  come  to  the  con- 
clusion that  the  molecule  of  hydrochloric  acid  con- 
tains one  atom  of  hydrogen.  We  know  by  analysis 
that  one  part  by  weight  of  hydrogen  in  hydrochloric 
acid  can  be  displaced  by  107.7  parts  by  weight  of 
silver,  with  the  production  of  silver  chlorid.  There- 
fore, 107.7  parts  by  weight  of  silver  (which  has  been 
set  as  the  atomic  weight  of  silver)  is  equivalent  to 
one  acid  hydrogen  atom. 

It  is  quite  easy  for  us  to  prepare  silver  lactate  and 
to  analyze  the  salt.  We  find  that  the  same  weight 
of  silver  (107.7)  as  is  equivalent  to  one  molecule  of 
hydrochloric  acid  (36.5)  is  also  equivalent  to  90 
parts  of  lactic  acid.  Lactic  acid,  therefore,  contains 
one  acid  hydrogen  atom  and  has  a  molecular  weight 
of  90. 

The  formula  CHjO,  however,  gives  us  a  molecular 
weight  (i 2  +  2-1-  16  =  30)  of  30.  We  must,  there- 
fore (30  X  3  =  90),  triple  our  formula  CHjO,  and 
write  the  formula  for  lactic  acid  (CH20)3.'  We  have 
thus  found  our  previously  unknown  "n"  to  be  3. 

We  know,  nevertheless,  that  the  body  trioxymethy- 
lene  has  the  formula  (CH20)3  (i.e.,  it  is  identical  with 
lactic  acid  in  elementary  composition  and  molecular 
weight) ;  and  we  are,  consequently,  still  without  means 
for  saying  why  we  should  expect  the  two  bodies  to  be 
so  very  dififerent  in  their  properties  as  we  know  them 
to  be.     When  we  come  to  studv  the  structures  of  the 


574  PHARMACEUTIC    CHEMISTRY. 

respective  molecules,  we  will  be  furnished  with  our 
desired  explanation. 

We  will  now  consider  another  example :  Ethane  is 
a  well-known  gas.  Analysis  shows  it  to  have  the 
following  composition: 

Carbon        =   4  parts   (80%). 
Hydrogen    =    1    part    (20%). 

Calculate  the  empiric  formula: 

12       3  I 

The  hydrogen  atoms  are  thus  three  times  aS 
numerous  as  the  carbon  atoms  in  the  molecule  of 
ethane.  We  thus  arrive  at  :he  empiric  formula: 
(CH3),. 

But  we  fmd  that  ^  of  the  hydrogen  in  the  ethane 
molecule  may  be  replaced  by  chlorin,  with  the  pro- 
duction of  the  definite  body,  ethyl  chlorid.  The 
ethane  molecule  mlist,  therefore,  contain  at  least  six 
hydrogen  atoms  and  the  formula  must  be  CoH^;  i.e., 
"n"  here  is  equal  to  two. 

Molecular  Weight  by  Avogadro's  Laic. — The  famous 
law  of  the  Italian  physicist,  Avogadro,  may  be  stated 
thus:  "Equal  volumes  of  all  gases,  at  the  same 
temperature  and  pressure,  contain  equal  numbers  of 
molecules."  It,  obviously,  follows  at  once,  from  this 
law,  that  the  relative  weights  of  the  molecules  of  the 
various  gases  are  proportional  to  the  relative  densi- 
ties of  the  gases. 

It  is,  therefore,  in  fixing  molecular  weights  by  the 
application  of  Avogadro's  law,  first  necessary  to  fix 


DETERMINATION   OF    MOLECULAR   WEIGHT.      575 

the  molecular  weight  of  hydrogen  (the  hydrogen  atom 
being  the  unit  of  mass) ;  and  then  to  determine  the 
densities  of  other  gases  relative  to  the  density  of 
hydrogen.  The  hydrogen  molecule  is  known  to 
contain  at  least  two  atoms  of  hydrogen;  and  is  not 
known  to  contain  more  than  two  atoms.  The 
molecule  of  hydrogen,  therefore,  weighs  two.  The 
density  of  hydrogen  is  taken  as  one.  The  molecular 
weight  of  hydrogen  being,  thus,  twice  its  density,  it 
follows  that  the  molecular  weight  of  any  gas  is  twice 
its  density  (compared  with  hydrogen). 

So,  in  order  to  set  the  molecular  weight  of  any 
body  by  the  law  of  Avogadro,  we  determine  how 
many  times  heavier  is  any  volume  of  the  body  in  the 
gaseous  state  than  the  same  volume  of  hydrogen. 
The  density  figure  being  determined,  it  is  multiplied 
by  two;  and  the  product  is  the  molecular  weigh't  of 
the  body  (in  its  gaseous  state) . 

This  method  for  determining  molecular  weights  is 
far  simpler  and  much  more  direct  than  the  chemical 
method;  but  it  is  only  applicable  to  gases  and  to  such 
liquids  and  solids  as  can  be  vaporized  without  de- 
composition. 

The  molecular  weight  of  a  body  as  set  by  purely 
chemical  methods  is  always  identical  with  the 
molecular  weight  determined  by  the  application  of 
Avogadro's  law. 


37 


576 


PHARMACEUTIC   CHEMISTRY. 


Examples: 

Gas 

/ 

Density 
(Hydrogen  =  i) 

Molecular  weight 
Density  X  2 

Steam 

Hydrochloric  acid.  . 
Ethane 

9- 

i8.2S 

15- 

32.25 
etc. 

18. 

36.5 

30- 

64.5 

etc. 

Ethyl  rhlorid 

etc. 

The  two  methods  of  vapor  density  determination 
prominently  mentioned  are: 

{a)  THE  CRYOSCOPIC  METHOD.— Depending 
upon  the  depression  produced  in  the  freezing-point 
of  a  solvent  by  a  known  weight  of  the  substance. 
This  was  the  original  method  and  known  as  the 
"freezing-point  method"  or  "Beckmann  method." 

{b)  THE  VICTOR  MEYER  METHOD.— Depend- 
ent, as  stated  before,  on  the  comparison  of  the  vapor 
density  with  a  standard  (hydrogen).  The  substance  is 
converted  into  a  vapor,  which  displaces  air.  This 
vapor  is  caught  in  a  graduated  tube  of  the  apparatus. 
The  collected  volume  of  gas  is  corrected  for  tempera- 
ture and  pressure  to  o°  and  760  mm.  of  mercury. 
The  weight  of  this  corrected  volume  is  compared  with 
the  weight  of  the  same  volume  of  hydrogen  (stand- 
ard). To  illustrate:  0.073  g"^-  ^^  ether  displaced 
25.3  c.c.  of  air.  The  column  of  displaced  air  was 
read  at  21.5°  and  718.6  mm.  pressure.  What  was 
the  volume  of  the  ether  vai)t)r? 


^5-3  X 


273- 


73-  +  21.5- 


23.46  QX.  of  vapor. 


TOXICOLOGY.  577 

This  corrected  for  pressure: 

718.6  less  19. 1   (vapor  tension  of    HjO  at  21.5°) 
=  699.5  iTim. 
Then — 

23.46  c.cX      ^^'^     =21.5  c.c.  of  ether  vapor  — 

at  0°  C.  and  760  mm.  pressure. 

This  volume  of    hydrogen  weighs,     — ^^ — l_v  = 

1. 000 

0.00197  gram  of  H2. 

The  quantity  of  ether  originally  taken  divided  by 

the  equi\alent  weight  of   hydrogen,       '^'■^      =37-6 

specific  gravity  of  the  ether  vapor. 

TOXICOLOGY. 

Toxicology  is  a  branch  of  medical  science  which 
treats  of  poisons.  In  this  short  article  are  included 
the  definitions,  effects  on  the  living  body,  symptoms 
and  treatment  within  the  body.  Also  an  abstract  of 
the  Pennsylvania  poison  law. 

True  poison  may  be  defined  as  a  substance  which 
when  absorbed  by  the  system  produces  great  physical 
injury  or  death.  Exami)les:  hydrocyanic  acid,  mor- 
phine, strychnine. 

A  corrosive  poison  is  a  substance  which  destroys 
the  tissues  with  which  it  comes  in  contact.  Examples : 
the  acids,  like  sulfuric  and  nitric. 

These  two  main  classes  of  poisons  should  be 
distinguished;  thus:  Sulfuric  acid,  which  is  a  cor- 
rosive, burns  the  tissues  with  which  it  comes  in  con- 
tact; strychnine,  which  is  a  true  poison,  on  the  other 


578  PHARMACEUTIC   CHEMISTRY. 

hand,  will  do  no  injury  lo  the  tissues,  but  when  ab- 
sorbed into  the  blood  it  will  produce  death. 

Sulfuric  acid,  largely  diluted,  loses  its  corrosive 
properties;  strychnine  is  no  less  poisonous  whatever 
the  dilution. 

Some  poisons,  like  corrosive  sublimate  and  arsenic, 
possess  the  properties  of  both  true  and  corrosive 
poisons,  and  are  called  irritant  poisons.  The  State 
Pharmaceutical  Examining  Board  in  their  instruc- 
tions to  the  pharmacists  regard  as  a  poison,  any  drug, 
chemical  or  preparation  which,  according  to  standard 
works  on  medicine  or  materia  medica,  is  liable  to 
be  destructive  to  adult  human  lije  in  quantities  oj 
sixty  grains  or  less. 

Substances  which  produce  deleterious  effects  or  cause 
death  due  solely  to  mechanic  action  are  not  poisons. 
The  taking  into  the  system  of  such  substances  as 
crushed  glass,  metal  filings,  boiling  water,  etc.,  may 
produce  injury  or  death  due  solely  to  mechanic  action. 

A  cumulative  poison  is  one  that  slowly  collects  in  the 
system  when  taken  jor  some  time.  Such  arc  digitalis, 
mercury,  lead,  iodin,  etc. 

Poisons  may  be  administered  with  some  other 
criminal  intent  than  that  of  murder;  the  criminal 
administration  of  abortifacients  and  the  use  of 
narcotics  in  attempted  rob])eries,  etc.,  being  well- 
known  examples. 

The  effects  of  poisons  arc  both  local  and  remote. 
'The  jornier  being  the  direct  impression  on  the  tissue 
with  which  the  poison  may  come  in  contact  {e.g.,  the 
corrosive  effect  of  the  mineral  acids  on  the  skin  or 


ANTIDOTES.  579 

mucous  membrane).  The  latter  are  those  resulting 
from  the  action  oj  the  poison  upon  the  blood,  brain  or 
spinal  cord  after  having  gained  entrance  into  the 
system  (e.g.,  the  tetanic  effect  of  a  large  dose  of 
strychnine  on  the  spinal  cord  after  being  absorbed 
from  the  stomach).  Some  poisons  act  both  locally 
and  remotely  (e.g.,  arsenic  acts  locally  on  the  stomach 
and  remotely  on  the  brain) .  The  usual  symptoms  of 
poisoning  are  due  to  the  remote  effects  and  are  of 
value  in  the  diagnosis  of  a  case. 

Various  conditions  which  affect  the  toxic  action  of 
poisons:  (i)  Dose;  (2)  age;  (3)  habit;  (4)  idiosyn- 
crasy; (5)  state  of  health;  (6)  the  condition  in  which 
the  poison  is  administered;  (7)  the  mode  of  intro- 
duction into  the  system;  (8)  the  amount  of  food  in  the 
stomach  at  the  time  the  poison  is  administered  or 
taken;  (9)  combination  of  poisons. 

Poisoning  may  be  acute,  when  produced  by  taking 
one  large  dose  of  poison ;  chronic,  when  produced  by 
long  continued  absorption  of  minute  quantities  of 
the  poison;  thus:  mercurialism,  produced  by  long- 
continued  dosing  with  mercury  salts;  saturnism,  pro- 
duced in  painters  and  plumbers  working  with  lead 
(lead-poisoning);  iodism,  cinchonism,  etc.,  are  all 
forms  of  chronic  poisoning. 

AN  ANTIDOTE  is  any  measure  or  agent,  which 
counteracts  the  effects  of  a  poison  or  an  attack  of 
disease.  Antidotes  are  divided  into  mechanic,  chemic 
and  physiologic. 

Examples  of  MECHANIC  ANTIDOTES  may  be  had 
in  the  stomach-pump,  demulcents,  as  flour  paste, 


580  PHARMACEUTIC   CHEMISTRY. 

mucilages,  fixed  oils  and  egg  albumen.  This  last 
agent  serves  also  as  a  chemical  antidote  for  copper 
and  mercury,  forming  albuminates  (excess  should  be 
avoided  in  mercury  poisoning  as  it  forms  a  soluble 
double  albuminate). 

CHEMIC  ANTIDOTE  is  one  which  combines  with 
the  poison,  forming  harmless  or  insoluble  compounds; 
thus,  magnesium  oxid  with  the  corrosive  acids  forms 
harmless  sulfate,  chlorid  or  nitrate,  etc.;  common  salt 
precipitates  lunar  caustic  and  other  silver  salts  forming 
insoluble  silver  chlorid. 

A  PHYSIOLOGIC  ANTIDOTE,  also  called  "an- 
tagonist," is  one  which  produces  opposite — antago- 
nistic— effects  in  the  system;  thus,  physostigma  is 
antagonistic  to  strychnine ;  digitalis  antagonizes  aco- 
nite; atropine  a-nidigomzts  morphine.  The  physiologic 
antagonists  are  best  administered  hypodermically. 

CONTRAINDICATION  OF  ANTIDOTES.— The 
stomach-pump  should  never  be  used  in  strong 
mineral  acid  or  oxalic  acid,  strong  alkali  or  corrosive 
sublimate  poisoning  (perforation  of  esophagus  or 
stomach  may  result).  Alkalis,  should  never  be  used 
in  neutralizing  oxalic  acid  (the  alkalin  oxalates  are 
poisonous  and  more  soluble) ;  the  alkali  carbonates 
are  contraindicated  in  corrosive  acid  poisoning  (COo 
is  given  off,  which  is  apt  to  rui)ture  the  corroded 
stomach  and  intestines).  Oils  should  never  be  used 
in  phosphorus,  j^henol,  creasote  and  cantharides 
poisoning  (they  dissolve  phos])horus  and  canthari- 
din,  etc.). 

TREATMENT  OF  UNKNOWN  POISONING.— In 


SYMPTOMS    OF    POISONING.  58 1 

the  case  where  the  poison  is  unknown,  administer 
JeauneVs  universal  antidote^  composed  of  solution 
ferric  sulfate,  75  c.c;  magnesium  oxid,  60  gm.; 
animal  charcoal,  30  gm.;  water,  600  c.c;  give  in  2 
wineglassful  doses  every  3  minutes.  This  is  also 
known  as  the  ^^ mulHple  antidote,"  and  acts  as  fol- 
lows: The  magnesia  neutralizes  any  acid  present, 
the  iron  salt  combines  with  any  arsenical  poison, 
and  the  charcoal  absorbs  or  precipitates  any  alkaloid. 
This  treatment  should,  if  necessary,  be  followed  with 
stimulants  until  the  physician  arrives. 

The  STIMULANTS  generally  used  in  poisoning 
cases  are:  brandy,  whisky,  alcohol,  ether,  tincture  of 
capsicum  per  rectum,  strong  tea  or  coffee.  Strong 
coffee,  preceded  by  emetic  and  a  little  tannin,  is  a 
reliable  antidote  for  the  narcotic  (solanaceae)  poisons. 

SPECIAL     SYMPTOMS     SUGGESTING     CERTAIN 
COMMON  POISONS. 

Organic. 
(i)  Aconite:  numbness,  tinghng  and  paralysis. 

(2)  Alcohol  (acute):  unconsciousness,  dilated  pu- 
pils, cold  skin. 

(3)  Belladonna,  atropine:  active  delirium,  dilated 
pupils,  hot  skin,  etc.  (this  applies  to  all  the  solana- 
ceae). 

(4)  Conium:  paralysis  of  limbs;  vertigo,  convul- 
sions, mind  clear,  double  vision. 

(5)  Digitalis:  heart  very  slow,  rapid  during  move- 
ment, with  nausea,  pain,  vertigo,  disturbed  vision. 

(6)  Headache    powders    (phenacetin,    antipyrin. 


582  PHARMACEUTIC    CHEMISTRY. 

acetanilid) :   depression,   vomiting,   blueness  of  lips 
chilliness,  collapse. 

(7)  Nux  vomica:  severe  convulsions  and  s])asms, 
opisthotonos,  clear  intellect  until  the  end. 

(8)  Opium  and  its  preparations:  unconscious- 
ness, contracted  pupils,  congestion. 

(9)  Phenol  (carbolic  acid) :   note  odor  or  stains. 

(10)  Ptomain  or  mushroom  poisoning:  severe 
vomiting  and  purging,  chills,  collapse. 

(11)  Santonin:  yellow  color  of  urine;  \cllo\v  vision. 

Inorganic. 

(i)  Acids  and  corrosive  irritants:  great  pain,  cold 
skin,  collapse. 

(2)  Antimony  and  copper:  same  as  above;  but  in 
the  latter  the  vomited  matter  is  green  or  blue. 

(3)  Arsenic:  severe  vomiting,  severe  burning  in 
the  mouth,  esophagus  (gullet)  and  stomach,  bloody 
stools,  convulsions,  cold  sweats,  coma  (unconscious- 
ness) . 

(4)  Alkalis:  severe  burning  in  throat  and  stom- 
ach, stricture  of  esophagus,  violent  pains  in  stomach, 
cold  skin,  etc. 

(5)  Corrosive  sublimate:  practically  the  same 
symptoms  as  arsenic,  but  appearing  more  rapidly. 

(6)  Hydrocyanic  acid  and  cyanids:  death  ra])id, 
symptoms  rarely  noted.  Short  convulsions,  odor  of 
almond  oil  may  be  noticeable. 

(7)  lodin,  bromin:  similar  sym})toms  to  last,  but 
not  quite  so  severe. 

(8)  Lead  salts:  burning  pains  in  throat  and  stom- 


TREATMENT   IN   CASES    OF    POISONING.  583 

ach,  thirst,  intense  colicky  pains  in  al:)d.omen.  In 
chronic  poisoning:  severe  colic  (lead  colic),  paralysis 
of  hands  and  feet  (lead  palsy) ;  blueness  of  gums, 
obstinate  constipation. 

(9)  Mineral  acids:  severe  burning  in  throat  and 
stomach,  severe  vomiting  of  black  or  reddish  matter, 
convulsions,  pains  in  bowels. 

(10)  Phosphorus:  Abdominal  pains,  severe  vomit- 
ing (having  odor  of  garlic),  jaundice,  suppressed 
urine,  delirium  (vomited  matter  phosphorescent  in 
the  dark). 

(11)  Silver  nitrate  (treatment  same  as  antimony 
and  copper) :  hard  white  patches  about  mouth 
(turning  black  in  time). 

GENERAL  METHOD  OF  TREATMENT  OF  CASES 
OF  POISONING. 

In  the  treatment  of  cases  of  poisoning  the  following 
general  method  is  recommended: 

(i)  Remove  the  poison  from  the  stomach  or 
chemically  and  mechanically  antidote  the  poison. 

(2)  Administer  physiologic  antidotes  or  adopt 
such  measures  as  will  antagonize  the  action  of  that 
portion  of  the  poison  which  has  been  absorbed. 

(3)  Promote  the  elimination  of  that  portion  of  the 
poison  which  has  been  absorbed  from  the  system  by 
resorting  to  such  means  as  the  nature  of  the  poison 
may  suggest. 

(4)  Combat  any  dangerous  symptoms  and  en- 
deavor to  keep  the  patient  alive  until  the  toxic 
effects  have  disappeared. 


584  PHARMACEUTIC   CHEMISTRY. 

These  general  methods  require  brief  discussion: 

(i)  Removal  of  the  poison  from  the  stomach  may 
be  accomplished  by  the  induction  of  vomiting  by  the 
use  of  emetics  or  by  tickling  the  fauces  or  by  the  use 
of  the  stomach-pump  or  stomach-tube. 

Emetics  are  classitied,  according  to  their  physio- 
logic action,  into  two  kinds: 

Peripheral  and  Centric. — Peripheral  emetics  act 
locally,  principally  upon  the  terminations  of  vagi  in 
the  stomach  or  locally  upon  the  terminations  of  the 
fifth  and  glossopharyngeal  nerves  in  the  mucous 
membrane  of  the  fauces.  Centric  emeti-cs  act  by 
stimulating  the  vomiting  center  in  the  medulla  ob- 
longata.    Some  examples  of  emetics: 

Flour  of  mustard,  ^  to  2  tablespoonfuls  in  ^  glass 
of  water. 

Tartar  emetic,  ^  to  i  grain  (wine  of  antimony 
contains  two  grains  of  tartar  emetic  to  each  ounce). 

Zinc  sulfate,  15  to  30  grains. 

Powdered  ipecac,  15  to  30  grains. 

Ammonium  carbonate,  15  to  30  grains. 

Copper  sulfate,  5  to  10  grains. 

Apomorphine,  yV  grain  hypodermically. 

Copious  draughts  of  tepid  water. 

Mustard  irritates  the  gastric  mucous  membrane 
and  is  a  good  example  of  a  peripheral  emetic. 
.\pomorphine  stimulates  the  vomiting  center  and  is  a 
typical  centric  emetic.  Antimony  (tartar  emetic) 
acts  in  both  ways:  it  irritates  the  gastric  mucous 
membrane  and  also  stimulates  the  vomiting  center 
in  the  medulla. 


TREATMENT    IN    CASES    OF    POISONING.  585 

Poisons  may  be  removed  from  the  stomach  by 
means  of  the  stomach-pump  or  the  stomach-tube, 
and  the  stomach  in  the  use  of  either  may  at  the  same 
time  be  washed  out. 


586  PHARMACEUTIC    CHEMISTRY. 

POISONS  AND  THEIR  ANTIDOTES. 


Poison 


(i)  Mineral  Acids. 

(H,S04  HNO.,  HCl 
and  nitro  -  hydro- 
chloric acid.) 


(2)   Vegetable  Acids. 

(Oxalic  acids  and 
salts;  tartaric  acids 
and  salts.) 


(3)  Alkalis. 

■  (NaOH,  KOH,NH4- 
OH  and  their  car- 
bonates.) 


.\ntidotcs 


Give     no     emetic.      Magnesia 
mi.xed  with  water,  milk,  whit- 
ing,   fixed    oils,    demulcents, 
Laudanum  (20  drops)  if  much 
pain.    (No  stomach-pump.) 


Chalk,  whiting,  air-slacked  lime 
with  vinegar.  (No  soda  or 
potash  to  neutralize  acid.) 
Mustard  water,  olive  oil,  de- 
mulcents and  stimulants. 
{No  stomach-pump.) 

Warm  water  till  emetic;  vinegar, 
lemon  juice  or  citric  acid. 
Olive  oil,  demulcents,  and 
Tr.  opium  (20  drops)  if  much 
pain.    {No  stomach-pump.) 


(4)   Barium,  lead  and  their  \  Epsom  {h  oz.)  or  Glauber's  salt 
salts.  (r     oz.)    in     water.     Emetic 

(mustard  water),  milk  and 
demulcents,  and  laudanum  if 
needed. 


(5)  Arsenic  and  all  its 
compounds. 


(6)  Antimony  salts,  can- 
tharides,  colchicum, 
elaterium,  io  din, 
copper,  mercury, 
croton  oil,  savin, 
tansy,  potass,  bi- 
chromate, tin  and 
zinc  salts. 


Emetic  (mustard  water),  hy- 
droxid  of  iron  or  hydroxid  of 
iron  with  magnesia,  olive  oil, 
albumen,  demulcents  and  Tr. 
opium. 

Albumen  diffused  in  water. 
Emetics  (warm)  water  with 
NaHCOj  or  mustard),  strong 
tea  or  coffee,  or  tannin,  stimu- 
lants, Tr.  opium  (if  needed) 
and  demulcents. 


POISONS    AND    THEIR    ANTIDOTES.  587 

POISONS  AND   THEIR  ANTIDOTES.— Cow/mwe^i. 


Poison 


Antidotes 


(7)     Niix     vomica     and] 
strychnine. 


(8)  Silver  nitrate. 

(9)  Cannabis  indica,  opium 

and  morphine. 


(10)  Aconite,    digitalis,    er- 

got, lobelia,  tobacco, 
veratrum,  bella- 
donna, coniu m , 
henbane,  santonin, 
stramonium,  cala- 
bar bean. 

(11)  Phosphorus. 

(12)  Alcohol,    chloral,  ether, 

chloroform. 


(13)  Hydrocyanic  acid  and 
the  cyanids. 


Emetics  (mustard  water),  pow- 
dered charcoal,  iodized  starch 
or  tannin.  To  relieve  spasms 
inhalations  of  chloroform  or, 
internally,  25  grs.  chloral  hy- 
drate or  i  oz.  potassium  bro- 
mid.   Lose  no   time. 

Sodium  chlorid,  emetics  (mus- 
tard  water),  demulcents. 

Emetics  (mustard  water)  or 
stomach-pump,  cold  affusions, 
strong  tea  or  coffee;  electro- 
magnetism.  Keep  patient 
awake  and  in  motion.  Artifi- 
cial respiration. 

Emetics  (mustard  water),  strong 
tea  or  coffee.  Hypodermics 
of  morphine;  powdered  char- 
coal; stimulants,  (whisky),  etc. 
Warmth  to  extremities  and 
artificial  respirations. 

Emetics  (CUSO4,  3  grains  every 
5  min.)  f3i  old  oil  turpen- 
tine, Mg.SO^  (^  oz.).    No  oils. 

Emetics  (mustard  mixture), 
stomach-pump,  strong  coffee 
or  tea,  cold  affusions,  artificial 
respiration,  mustard  poultice 
to  limbs. 

Mild  inhalations  of  ammonia, 
cold  applications  to  head;  in- 
ternally, the  following  three 
solutions  in  order  given:  {a) 
Potassium  carbonate,  1 5 
grains,  in  H2O,  if§;  (6)  iron 
sulfate,  i5grainsin  H2O,  ifo  ; 
(c)  tincture  iron  chlorid,  ifo. 
(This  forms  the  harmless 
"Prussian  blue.") 


588  PHARMACEUTIC    CHEMISTRY. 

ABSTRACT    OF    THE    PENNSYLVANIA    POISON 
LAW. 

Unregistered  dealers  may  sell  the  commonly  used 
drugs  and  medicines  in  packages  that  have  been 
legally  prepared  by  or  under  the  supervision  of  regis- 
tered pharmacists. 

After  the  law  in  regard  to  the  mixing  or  com- 
pounding and  dispensing  of  drugs,  medicines  and 
medicinal  preparations  has  been  complied  with,  it  is 
permissible  for  general  storekeepers  and  merchants 
who  are  not  registered  pharmacists  to  sell  legally 
prepared  packages  of  the  commonly  used  medicines 
and  poisons,  subject,  of  course,  to  the  same  restric- 
tions that  are  placed  upon  properly  qualified  and 
registered  pharmacists  in  regard  to  purity  and 
strength  under  the  Act  of  May  25,  1897;  and  under 
the  restrictions  of  Section  10  of  the  Act  of  1887, 
which  is  as  follows: 

"Section  10. — A  poison,  in  the  meaning  of  this 
Act,  shall  be  any  drug,  chemical  or  preparation 
which,  according  to  standard  works  on  medicine  or 
materia  medica,  is  liable  to  be  destructive  to  adult 
human  life  in  quantities  of  sixty  grains  or  less. 

No  person  shall  sell  at  retail  any  poisons  except  as 
herein  provided,  without  affixing  to  the  bottle,  box, 
vessel  or  package  containing  the  same  a  label, 
printed  or  plainly  written,  containing  the  name  of  the 
article,  the  word  ^^  poison  "  and  the  name  and  place  of 
business  of  the  seller;  nor  shall  he  deliver  poison 
to  any  person  without  satisfying  himself  that  such 
]K)i.son  is  to  be  used  for  legitimate  purposes. 


THE    PENNSYLVANIA    POISON   LAW.  589 

It  shall  be  the  further  duty  of  any  one  selling  or 
dispensing  poisons,  which  are  known  to  be  destruc- 
tive to  adult  human  life  in  quantities  of  five  grains  or 
less,  before  delivering  them,  to  enter  in  a  book  kept 
for  this  purpose  the  name  of  the  seller,  the  name  and 
residence  of  the  buyer,  the  name  of  the  article, 
quantity  sold  or  disposed  of  and  the  purpose  for 
which  it  is  said  to  be  intended,  which  book  of 
registry  shall  be  preserved  for  at  least  two  years,  and 
shall  at  all  times  be  open  to  the  inspection  of  the 
coroner  or  courts  of  the  county  in  which  the  same 
may  be  kept. 

The  provisions  of  this  section  shall  not  apply  to 
the  dispensing  of  physicians'  prescriptions  specifying 
poisonous  articles,  nor  to  the  sale  to  agriculturists  of 
such  articles  as  are  commonly  used  by  them  as  in- 
secticides. Any  person  failing  to  comply  with  the 
provisions  of  this  section  shall  be  deemed  guilty  of  a 
misdemeanor,  and  upon  conviction  thereof  shall  be 
punished  by  a  fine  of  not  less  than  five  nor  more  than 
fifty  dollars  for  each  and  every  offense. 

Wood  or  methyl  alcohol  cannot  he  used  in  the  com- 
pounding of  pharmaceutical  preparations. 

The  standards  of  law  in  this  State  do  not  permit 
the  use  of  wood  or  methyl  alcohol  (this  includes 
Columbian  spirits,  colonial  spirits,  kahol,  etc.)  in 
compounding  and  preparation  of  formulae  contained 
in  the  U.  S.  Pharmacopoeia  and  National  Formulary, 
and  any  one  so  using  it  will  be  subject  to  the  penal- 
ties of  the  Act  of  May  25,  1897,  and  will  be  promptly 
dealt  with  by  this  Board  according  to  law. 


590  PHARMACEUTIC    CHEMISTRY 

Penalty:  Fine  ($ioo),  imprisonment  (90  days); 
either  or  both  at  discretion  of  court. 

AN  ACT. 

Regulating  the  sale  or  prescription  of  cocaine,  or  of  any  patent 
or  proprietary  remedy  containing  cocaine,  and  prescribing 
penalties  for  the  violation  thereof. 

Section  i.  Be  it  enacted,  etc.,  That  no  person 
shall  sell,  furnish  or  give  away  any  cocaine,  or  any 
patent  or  proprietary  remedy  containing  cocaine, 
e.xcept  upon  the  prescription  of  a  registered  practic- 
ing physician,  or  of  a  dentist,  or  of  a  veterinarian; 
nor  shall  any  such  prescription  be  refilled;  nor  shall 
any  physician,  dentist  or  veterinarian  prescribe 
cocaine,  or  any  patent  or  proprietary  remedy  con- 
taining cocaine,  for  any  person  known  to  such 
physician,  dentist  or  veterinarian  to  be  an  habitual 
user  of  cocaine:  Provided,  That  the  provisions  of  this 
Act  shall  not  apply  to  persons  engaged  in  the  whole- 
sale drug  trade,  regularly  selling  cocaine  to  persons 
engaged  in  the  retail  drug  trade. 

Section  2.  Any  person  violating  any  of  the  provi- 
sions of  this  act  shall  be  sentenced  to  pay  a  fine  of  not 
more  than  one  hundred  dollars  and  undergo  an 
imprisonment  of  not  more  than  six  months,  or  both, 
or  either  at  the  discretion  of  the  court. 

Approved — The  22d  day  of  April,  A.  D.   1903. 


INDEX 


Abietic  anhydrid,  503 
Acacia,  502 
Acetaldehyd,  335 
Acetaldoxirn,  380 
Acetal  salicylate,  326 
Acetamid,  383 
Acetanilid,  437,  439,  441 

poisoning,  582 
Acetone,  340,  341 
dioxy,  395 
collodion,  342 
properties,  341 
sodium  bisulfite,  341 
Acetonitril,  376,  384 
Acetophenone,  478,  479 
Acetoxime,  380 
Acetphenetidin,  458 
Acetyl  benzene,  478 
chlorid,  3  71 
group,  372 

para-amido    phenyl  salicyl- 
ate, 491 
salicylic  acid,  492 
Acetylene  series,  242 

table,  243 
Acids,  16,  67,  182,  212 
abietic,  547 
acetic,  345,  351 
acetic  glacial,  351 
anhydrid,  372 
amido,  367 
amino,  384 
acetyl  salicylate,  492 
acrylic,  299 
adipic,  358 
alcohol,  480 
alphahydroxy-propionic, 

368 
amidoacetic,  367 

benzoic  (ortho),  486 
amino  acetic,  384 

propionic  (alpha),  385 
succinic,  366 
succinamic,  366 
anhydrids,  372 

mixed,  372 
anisic,  481 
anthranilic,  486 
arachidic,  346,  358 


38 


Acids,  aromatic,  481 

hydroxy,  480 

preparation,  482 

table,  480 
arsenous,  74 
aspartic,  366 
atropic,  480 
barbituric,  392 
basicity,  67 
behenic,  346 

benzoic,  480,  482,  483,  47; 
476,  385,  429    • 

derivatives,  483 
benzenepentacarboxylic, 

480 
beta  cyanpropionic,  364 

naphthylortho-oxymeta- 
toluic,  516 
brombenzoic-meta,  485 

ortho,  485 

para,  485 
butyric  normal,  355 

fermentation,  355 
capric,  345 
capryhc,  345 
caproic,  345 
carbamic,  361 
carbazotic,  454 
carbolic  poisoning,  582 

antidote  (see  Phenol) 
carbonic,  73,  358,  359 

derivatives,  361 
camaubic,  346 
catechutannic,  495 
cerotic,  346 
chloric,  71 
chlorids,  370 
chlorous,  71 
cinchomeronic,  530 
cinchotannic,  495 
cinnamic,  488,  489 
citric,  300 
copaibic,  505 
coumaric,  481 
crotonic,  244 
cumic,  488 
cyanacetic,  359 
cyanic,  378 
cyanuric,  378 


591 


592  I 

Acids,  cynamic,  480 
daturic,  346 
derivatives  of,  370 
dextrq-tartaric,  301 
dialuric,  392 
diazo-benzene     sulfonic, 

428 
dibasic,  72 

organic,  358,  359 
dichlor-acetic,  370 
digallic,  494 

dihydroxybarbituric,  392 
dithiocarbonic,  381 
ellagic,  493 
ethylsulfonic,  373 
formic,  34S.  349 
fulminic,  377 
gallic,  381,  493.  494 
gallo,  tannic,  494 
glutaric,  358 
glycerophosphoric,  322 
glycoUic,  367,  368,  399 
guaiacic,  504 
guaretic,  504 
gummic,  502 
halids,  212 
hippuric,  384 
hydriodic,  38 
hydrochloric,  70 
hydrocyanic,  69 

poisoning,  582 

antidote,  587 
hydrocynamic,  480 
hydrofluoric,  33 
hydrosulfuric,  72 
hydroxy,  348,  489 
hydroxypropionic,  367 
hydroxysuccinic,  366 
hyenic,  346 
hypochlorous,  71 
hypophosphorous,  70 
hyposulfuric,  72 
isoacetic,  346 
isobutyl  acetic,  345 
isobutyric,  345,  356 
isonicotinic,  529 
isophthalic,  432 
isosuccinic,  365 
isothiocyanic,  379 
isovaleric,  345.  3S6,  357 
kramerotannic,  495 
lactic,  368 

varieties,  369 
laevo-tartaric,  301 
lauric,  345,  358 
lignoceric,  346 
malic,  365,  366 
malonic,  358,  359,  364 
mandelic,  481 
mastichic,  504 
mellilotic,  481 
mellissic,  346 


Acids,  mellitic,  480 
mesetylenic,  480 
meso-tartaric,  301 
meta-oxy-benzoic,  480 
metaphosphoric.  70 
melhyl-ethyl-acetic,    345, 

357 
mineral  poisoning,  583 

antidote,  586 
monochlor-acetic,  370 
myristic,  345,  358 
naphthalene    sulfonic,    517, 

518 
naphthalic,  518 
naphthionic,  518 
naphthoic,  518 
nicotinic,  529 
nitric,  69 

nitrobenzoic  (ortho),  485 
(meta),  48s 
(para),  486 
nitrohydrochloric,  71 
nitrous,  68 
nomenclature,  68 
cenanthylic,  345 
oleic,  244 

organic  antidotes,  586 
organic  basicity,  347 
nomenclature,  368 
occurrence,  349 
preparation,  349 
properties,  348 
orsellinic,  481 
orthohydroxy-benzoic,  489 
orthophosphoric,  74 
oxalic,  358,  359.  Sf^i 
antidotes,  5S6 
toxicology,  363 
oxids,  183 
oxy,  348,  367 
oxytoluic,  481 
palmitic,  346 
parabanic,  391 
paralactic,  369 
paraoxy-benzoic,  480 
pelargonic,  345 
perchloric,  71 
phenol,  480 
I)henol-sulfuric,  452 
phenyl-acetic,  480,  488 
phenyl-acryllic,  488 
phenyl-propiolic,  480 
phenyl-propionic.  488 
phthalic,  432.  480 
phosphorous,  73 
picolinic,  529 
picric,  454 
pimelic,  358 
propionic,  34S.  354,  37^ 
protocatechuic,  481,  49 1 
prussic,  30,  69 
Scheele's,  30 


593 


Acids,  pyroligneous,  351,  352 

pyro-mellitic,  480 

pyro-phosphoric,  75 
sulfuric,  73 
tartaric,  303 

pyruvic,  368 

quercitannic,  495 

quinic,  481 

quinolinic,  530 

racemiff,  301 

salicylic,  480,  489,  490 

^arcolactic,  369 

silicic,  47 

sozalic,  452 

stearic,  346 

substitution,  370 

succinic,  358,  364 
normal,  365 

sulfanilic,  428 

sulfo-benzoic,  486 

sulfocyanic,  378 

sulfocarbolic,  452 

sulfuric,  702 
aromatic,  703 

sulfurous,  702 

tannic,  494 

tartaric,  301 

terephthalic,  432 

thiocarbonic,  381 

thiocyanic,  378 

thiosulfuric,  73 

toluic,  432,  480 
meta,  487 
ortho,  487 
para,  487 

tribasic,  74 

trichloracetic,  338 

tridecylic,  345 

trimethylacetic,  345,  357 

trioxyacryllic,  391 

trioxybutyric,  399 

trithiocarbonic,  381 

tropic,  481 

trimesic,  480 

undecylic,  345 

uric,  390,  391 
derivatives,  390 

valeric,  345.  356,  367 

vanillic,  481 

vegetable  antidote,  586 

xanthogenic,  381 

xylylic,  480 
Aconite  antidote,  587 

poisoning,  581 
Acrolein,  299 
Adhesion,  3 
Adjacent,  421 
Affinity,  chemical,  3 
Airol,  494 
Alabaster,  135 
Alanin,  385 
Alcohol,  206,  211 


Alcohol,  21 1 

absolute,  270 

allyl,  279 

amyl,  280 

anisyl,  474 

antidote,  587 

aromatic,  450,  472 

cinnamyL  473 

commercial,  270 

deodorization,  270 

diatomic,  282 

dilute,  270 

diphenyl,  479 

distillation,  269 

ethyl,  266 

grain,  266 

isomeric,  table  of,  278 

isomerism,  276 

isopropyl,  277 

manufacture,  269 

methyl,  264 

nomenclature,  276 

orthohydroxybenzyl,  473 

oxidation,  277 

paramethoxybenzyl,  474 

piperonyl,  474 

poisoning,  581 

polyatomic,  300 

preparation  of,  262 

primary,  260 

properties  of,  263 

propyl,  277 

salicylic,  473 

secondary,  262 

synthesis  of,  306 

table  of,  261 

tertiary,  262 

triatomic,  285 

vanil,  474 

vanillin,  474 

wood,  266 
Alcohols,  reaction  of,  332 

resin,  332 

salicylic,  476 

structure  of,  329 

table  of,  327 

valeric,  SS4,  SS7 
Aldehyd,  335,  211 

ammonia,  331 

anisic,  477 

aromatic,  472,  474 

benzal,  474 

benzoic,  549 

butyric,  554 

cinnamic,  476.  549,  5SS 

cuminic,  478 

formic,  333 

glyceric,  395 

glycollic  395 

group,  329 

hydroxy,  367,  395 

lauric,  557 


594  INI 

Aldehyd,      methylene-ether     of 
proto-catechuic,  478 

methyl-protocatechuic,  477 

preparation  of,  328 

properties  of,  328 

proto-catechuic,  477 
Aldobiose,  395 
Aldol,  336 
Aldoses,  395 
Aldotriose,  395 
Aldoximes,  331 
Aliphatic  series,  214 
Alizarin,  522,  523,  525 

blue,  524 

orange,  524 

synthesis,  522 
Alkali    metal   group,    140 

poisoning,  582 

antidotes,  586 
Alkaloid,  531 

animal,  538 

cadaveric,  538 

discussion  of,  536 

doses,  539,  S40 

extraction  of,  537 

myotic,  534 

nomenclature  of,  536 

occurrence.  536 

solubilities  of,  539,  540 

tests  for,  538 

table  of,  539,  540 

unofficial,  536 
Alkaloidal  salts,  537 
Alkyl,  430 

acetates,  372 

aniliri,  438 

halids,  213,  259 

sulfonic  acid,  373 
chlorid,  374 
Alkyl  sulfonic  ester,  373 
AUotropism,  184 
Alloxan,  392 
Alloy,  185 
Ally!  iso-thio-cyanate,   284,  379 

SS7 
Allyl  sulfids,  284,  382 
Aloin,  497,  498 

Alpha-methylhydroxylamin,  380 
Alum  (kinds  of),  118 

compounds,  119,  120 

dried,  119 

preparation,  118 
Aluminum,  1:7 

bronze,  118 

preparation,  1 1  7 

properties,  1 1  7 

tests,  121 
Amalgam,  185 
Amber,  503 
Amid,  383,  212 
Amido  azo  benzene,  448 

benzene,  43s 


Amido  compounds,  447 
Amid  phenol,  458 

propion,  383 
Amin,  212 

dimethyl,  541 

diphenol,  438,  440 

propyl,  541 

triethyl,  541 
Amins,  aromatic,  435 
varieties,  43? 

preparations,  386 

primary,  386 

secondary,  386,  388 

tertiary,  386,  388 

tri phenyl,  438 
Amino  acid,  384 

azo^benzene,  446 
Ammonia,  25 

tests,  i6s 
Ammoniac,  511 
Ammonium,  161 

carbonate,  362 

compounds,  162 

cyanate,  316,  203 

ichthyosulfonate,  4S3 

molybdate,  175 

picrate.  454 

propionate,  376 

sulfid  group,  108 

sulfo  cyanid,  314 

thio  cyanate,  378 
Amorphous,  184 
Amygdalin.  475,  497 
Amylacetate,  281,  326 
Amylene,  238 

hydrate,  281 
Amyl  methyl  ketone,  ss4 

nitrite,  281 
Amylopsin,  267 
Analysis,  elementary,  563 

organic,  561 

volumetric,  566 
Anethol,  554,  55  5 
Anhydrid,  183,  213 

abietitj,  503 

acetic,  373 

propionic,  312 

succinic,  365 
Anhydro  gluco  chloral,  339 
Anilin,  408,  435,  436 

alkyl,  438 

derivatives,  438 

dimethyl,  43O,  440 

dyes,  440 

hydrochlorid,  430 

methyl,  438,  439 

nitrate,  436 

salt.  436 

sulfate,  436 
Anions,  179 
Anisol,  452,  477 
Anode,  178 


595 


Antagonists,  580 
Anthracene,  408,  520 

substitution    products,    521 

synthesis,  520 
Anthracite,  28 
Anthra  quinon,  521 

beta    sulfonic    acid,     522 
Antidotes,  597 

chemic,  580 

contraindications,  580 

Jeaunel's  universal,  581 

mechanic,  579 

multiple,  581 

narcotic  poison,  581 

physiologic,  580 

table  of,  586,  587 
Antimony,  94 

compounds,  95 

poisoning,  582 

antidote,  586 

potassium  tartrate,  95 

preparations,  94 

properties,  94 

tests,  96 
Antipyrin,  535 

poisoning,  5S1 
Antitoxins,  542 
Apple  oil,  323 
Arabitol,  306 
Arachin,  297 
Arbutin,  497,  501 
Argols,  144.  302 
Armstrong's  nucleus,  415 
Aromatic  hydrocarbons,  407 

diketones,  479 
Arsenic,  89 

antidote,  586 

compounds,  90 

iodid,  91 

poisoning,  582 

preparations,  90 

properties,  90 

solution  (Fowler's),  91 

sulfid,  91 

tests,  93 

toxicology,  93 

wall  paper,  92 

white,  91 
Arsin,  388 

tertiary,  389 
Arsonium,  388 
Aryl,  430 
Asafetida,  509 
Aseptol,  452 
Asparagin,  366 
Asphalt,  503 
Aspirin,  492 
Asymmeteric,  369,  421 
Atmosphere,  61 

composition,  61,  62 

impurities,  63,  66 
Atomic  weights,   11 


Atomicity,  13 
Atropine,  S3i 

antidote,  587 

poisoning,  581 
Aubepine,  477 
Aurin,  463 
Australene,  544.  557 
Autointoxication,  541 
Azo  benzene,  446 

compounds,  445 

Baker's  ammonia,  162 

Baking  powder,  305 
Baking  soda,  153 
Balata,  548 
Balsams,  507 
Balsamic  resins,  503 
Balsam  of  fir,  506 

of  peru,  508 

of  styrax,  509 

of  tolu,  508 
Bamberger's  formula,  513 
Barium  compounds,  133 

oxids,  133 

salts,  antidote  for,  586 

tests,  133 

toxicology,  133 
Bases,  15,  182 

Basic  organic  compounds,  408 
Battery  ammonia,  162 
Bayer's  benzene  ring,  415 
Beckman  method,  576 
Bdelium,  510 
Beef  tallow,  294 
Beer  manufacture,  271 
Benzal  chlorid,  430.  435.  475 
Benzaldehyd,  475.  445 
Benzaldehyd  phenyl  hydrazone, 

445 
Benzamid, 
Benzene,  408,  417a,  441 

addition  compounds  of,  413 

amyl,    417b 

butyl,  417b 

constitution  of,  413 

derivatives  of,  418 

diazoamido,  448 

diazohydroxy,  449 

diazo  nitrate,  448 

dichlorid,  413 

dimethyl  ethyl,  417b 

dinitro,  426,  427 

disubstituted,  421 
identification  of,  422 

halogen  derivatives  of,  425 

hexabrom,  413 

hexabromid,  425 

hexachlor,  413,  425,  426 

hexahydrid,  413 

homologues,     synthesis    of, 
424 

hydrocarbons,  table  of ,  4 1 7a 


596 


Benzene,  hydroxy,  449 

isopropyl,  417a 

metadibrom,  422 

methyl,  424 

methyl  amido,  416 

monochlor,  425 

mono  substituted,  419 

nitro,  419 

nitrobrom,  418 

nitro  derivatives  of,  426 

ortho  dibrom,  422 

para  dibrom,  422 

para  sulfonic  acid,  428 

para  methyl  propyl,  433 

penta,  422 

penta  methyl,  417b 

properties  of,  413 

propyl  normal,  417a 

ring,  Bayer's,  415 

ring,  Kekule's,  413 

series,  407 

substitution  of,  413 

sulfonic  acid,  427,  428 

sulfo  derivatives  of,  427 

synthesis  of,  412 

tetra,  422 

tetra  methyl,  417b 

tribrom,  423 

tribromid,  413 

trichlor,  426 

triethyl,  417b 

tri-iodo,  413 

tri  methyl,  417a 

tri   substituted,    421,    423. 
424 
Benzidine,  446 

dyes,  446 
Benzenyl  chlorid,  430 
Benzoic  anhydrid,  484 
Benzoin,  508 
Benzol,  408,  411 
Benzonitril,  48s 
Benzophenone,  479 
Benzoquinon,  479 

sulfinid,  ,486 
Benzoyl  chlorid,  484 
Benzoyl  group,  484 
Benzoyl  glycin,  384 
Benzyl   alcohol,    434.    472,    4", 

476 
Benzylamin,  440 
Benzyl  benzoate,  484 

chlorid,  430.  434.  472 
Benzyledene  chlorid,  430 
Belladonna  poisoning,  581 

antidote  for,  587 
Beryllium,  176 
Betain,  38s 

Beta  methyl  hydroxylamm,  3S 
Beta  naphthol,  576 
Betol,  492 
Beverages,  269 


aichlorid -mercury,  poisoninK  by. 

582 
Biebrich  scarlet,  407 
Bismuth,  98 

beta-naphthol,  516 
Bismuth  compounds,  99.  loi 

gallo-oxy  iodid,  494 

preparations,  98 

properties,  98 
Bismuth  subgallate,  493 

tests  for,  loi 
Bisulfite  compounds,  330 
Bittern,  36 
Bituminous  coal,  28 
Blasting  gelatin,  404 
Blue  anilin,  46s 

methylene,  465 

Paris,  313 

Prussian,  313 

Williamson's,  313 
Bonds,  T3 

acetylenic,  210 

olefinic,  210 

paraffinic,  210 
Boquet,  322 
Borax,  154 
Bomeol.  548,  S49.  SS2    5S7 

esters,  548 
Bornyl  acetate,  548 
Boron,  45 
Bromal,  339 
Brandy,  274 
Brom  benzene,  444 
Bromelin,  267 
Bromin,  35 
Bromin  compounds,  37 

poisoning,  582 

antidote  (see  Cyanid) 

preparation,  36 

properties,  36 
Bromoform,  253 
Brucine,  534 
Burette,  567 
Burgundy  pitch,  506 
Butane,  229 
Butter,  294 

substitutes,  29s 
Butterine,  29s 
Butyl  chloral,  339 

hydrate,  339 
Butyline,  238 
Butyrin,  294 
Butyrone,  340 

Cacao  butter,  296 

oil,  297 
Cacodyl,  389 
Cadet's  liquid,  389 
Cadinene,    544.    546,    SS4.    555. 

SS7 
Cadmium,  104 

compounds,  105 


597 


Cadmium,  description  of,  105 
Caffein,  393,  534 
citrated,  534 
Calabar    bean,    antidote     for. 

Calcium,  135 

acetate,  341 

benzoate,  475 

carbid.  138 

compounds,  13s 

formate,  475 

oxylate,  364 

phosphate,  138 

preparations,  135 

properties,  13s 

tests,  X39 
Calcutta  niter,  143 
Calico,  470 
Calx,  136 

Camphene,  S47.  SS2,  SS7 
Camphor,  549,  557 

artificial,  S4S 

mono  bromated,  551 
Canada  balsam,  506 
Cannabis  indica,  587 
Cannel  coal,  28 
Candles,  manufacture  of,  296 
Cantharides,  antidote  for,  586 
Caoutchouc,  512 
Caprone,  340 
Caramel,  400 
Carbamid,  203,  360,  362 
Carbamin,  376,  439 
Carbazole,  520,  530,  531 
Carbhydrates,  212,  394 
Carbocyclic  series,  407 
Carbohydrate,  394 
Carbon,  26,  207 

amorphous,  28 

asymmetric,  369 

disulfid,  208,  557 

determination  of,  563 

forms  of,  207 

oxids  of,  29 

oxychlorid,  359 

source  of,  208 

tetra  chlorid,  253 

tetra  iodid,  255 

valence  of,  211 
Carbonate  group,  132 
Carbonyl,  208 
Carbonyl  chlorid,  359 
Carboxyl  group,  347 
Carmalite,  142 
Carvacrol,  457,  549 
Carvene,  545 
Carvone,  549.  SS4>  SS6 
Caryophyllene,  554,  555 
Catalase,  267 
Catalytics,  22 
Catechol,  460 
Cathion,  179 


Cathode,  178 
Celestite,  133 
Cellulose,  394,  403 
Cement,  120 

hydraulic,  121 
Portland,  121 
Roman,  121 
Ceramics,  120 
Cerium,  176,  177 
Cesium,  177 
Chain  closed,  210 

open,  210 
Chalk,  135 
Changes,  chemical,  6 

physical,  6 
Charcoal,  28 
Chemism,  3 
Chemical  change,  187 
Chemistry,  6 

of    carbon    compounds,  202 
compound  radicals,  201 

electro  179 

organic,  201,  205 
scope  of,  203 

physical,  179 
Chestnut  tannin,  496 
Chicle  gum,  548 
Chili  niter,  151 
Chloral,  250,  336 

antidote  for,  587 

alcoholate,  337 

formamid,  339 

hydrate,  337 

properties  of,  337 
Chloralamid,  339 
Chloralose,  339 
Chlor  benzene,  444 
Chloric  ether,  256 
Chloroform,  249 

antidote  for,  587 

purity  tests,  252 
Chlortoluene,  434 
Chlorin,  34 

acids,  35 

compounds,  35 

oxids,  35 

preparations,  34 

properties,  34 
Cholesterol,  296 
Cholin,  284 
Chromium,  122 

acids,  122 

alloys,  122 

anhydrid,  122 

compounds,  123 

pigments,  123 

preparation,  122 

properties,  122 

sulfate,  123 

toxicology  and  tests,  124 
Chrome  alum,  497 

green.  124 


598  I 

Chrome  yellow,  123 
Chromic  chlorid,  124 
Chromyl  chlorid,  124 
Chrysamin,  446,  447 
Chrysarobin,  497,  499 
Chrysene,  407 
Cinchonism    579 
Cinchonidine,  533 
Cinchonine,  S33 
Cineol,  551,  5S4,  SS5.  SS6 
Cinaldehyd,  476 
Citral,  S49.  556 
Citrene,  S4S 
Citronellal,  556 
Citronellol,  548,  549.  55^ 
Classification,  8 

of  compounds,  15,  211 
Closed-chain  series,  407 
Clovene,  S47.  SS4 
Coal  distillation,  410 

gas,  245 
Coal  tar,  407,  408 
Cobalt,  1 25 

compounds,  126 
inks  (sympathetic),  126 
Cocaine,  532 
law,  589 
Codeine,  533 
Cohesion,  3 
Coke,  29,  407,  409 
Colchicine,  534 
Colchicum  antidote,  586 
Collidin,  541 
Collodion,  321,  405 
Colophene,  544 
Colophony,  503 
Combustion  tube,  536 
Concrete,  121 
Congo  red,  447 
Coniine,  531 
Conium  poisoning,  587 

antidote,  587 
Copaiba,  505 

adulteration,  505 
Copal,  503 
Copper,  loi 

compounds,  102,  104 
properties,  102 
salts  antidote,  586 
tests,  1 04 
toxicology,  104 
Cordite,  290,  404 
Cork,  406 

Corrosive     acid     poisoning, 
582 
antidotes,  586 
Cotton,  403 
Cottosuet,  295 
Coumarin,  492 
Creatin,  385 
Creatinin,  385 
Creolin,  45s 


Creosol,  466 
Creosote,  455 
Cresol,  434.  454.  455 

compound  solution,  455 

para,  408 

propylmeta,  457 
Crcsylic  acid,  454 
Croton  chloral  hydrate,  339 
Cryolite,  151 
Cryoscopic  method,  576 
Crystal  violet,  360 
Cubebin,  544 
Cudbear,  467 
Cumene,  417a 
Cutch,  417a 

tannin,  496 
Cyamelide,  378 
Cyanhydrins,  330,  396 
Cyanic  acid,  316 
Cyanid,  212 

poisoning,  582 
antidote  for,  311,  587 
Cyanogen,  30,  310 

compounds,  310 
Cyanuric  acid,  316 
Cyclic  hydrocarbons,  407 
Cymene,  417a,  434,  443.  545 

hexahydroxy,  549 

Dammar,  503 

Dead  oil,  410 
Decay,  274 
Deliquescent,  185 
Density  vapor, 

determination  of,  576 
Dermatol,  493 

Determination,    vapor    density, 
576 

molecular  weight,  571 
Dextrin,  394,  402,  405 
Dextrose,  394,  398 
Diamins,  441 
Diamin  tetramethylene,  541 

pentamethylene,  541 
Diaminodiphenyl,  446 
Diamond,  27 
Diamyl  ketone,  340 
Diastase,  267 

Diazoamido  compounds,  447 
Diazobenzene,  442 

butyrate,  443 

chlorid,    450 

hydrochlorid,  443 

nitrate,  443,  444 

sulfate,  443 
Diazo  compounds,  418.  442 
Dibromanthroquinon,  522 
Diethyl-glycocol-amido-oxyben- 

zoic  methyl  ester,  491 
Diethyl  ketone.  340 
Diethylsulfondiethylmethane, 
343 


599 


Diethylsulfondimethylmethane, 

Digitalein,  500 

Digitalin,   French,   German   and 

Killiani,  500 
Digitoxin,  500 
Digitalis  poisoning,  581 

antidote,  587 
Dihexyl  ketone,  340 
Dihydroxytoluene,  466 
Di-isopropyl  ketone,  340 
Di-isobutyl  ketone,  340 
Dimethylamin,  386 
Dimethyl    aniline    azo    benzene 

sulfuric  acid,  429 
Dimethyl  ketone,  340 
Dimorphous,  184 
Dipentene,  546 
Diphenylamin,  437 
Diphenyl  ether,  452 
Diphenyl  ketone,  479 
Dippel's  oil,  436 
Dipropyl  ketone.  340 
Distillation  applied,  558 
Distillation,  dry,  245 

destructive,  245 
Diuretin,  535 
Dog  buttons,  534 
Dragon's  blood,  507 
Dried  gypsum,  139 
Dulcitol,  306 
Durene,  4176 
Dutch  liquid,  241 
Dyes,  468 

colloidal,  470 
Dyeing,  468,  469 
Dynamite,  290 

Ebonite,  512 

Efflorescent,  185 
Elastica,  512 
Elaterin,  497,  498 
Electrolysis,  180. 
Electrolyte,  180 
Electro-negative,  179 
Electroplating,  181 
Electro-positive,  178 
Electrotypes,  181 
Electrotyping,  180 
Elements,  4 
Elementary  matter,  4 
Elements  and  compounds,  10 
Elements,  classification  of,  169 
Elemi,  503 

Emetics,  classification  of,  584 
Enfleurage,  552 
Enteric  pills,  491 
Eosin,  461,  462 
Epicarin,  516 
Epsom  salts,  166 
Equations,  187 
analytic,  189 


Equations,  double   decomposit- 
ion, 191 

single  decomposition,  190 

synthetic,  189 

writing,  187 
rules,  188,  191 
Erlenmeyer's  formula,  513 
Erythritol,  301 
Esparto,  469 
Essence,  fruit,  321 
Essential  oils,  544 

constituents  of,  548 
Ester,  317,  323 
Ethane,  229 

density  of,  376 

derivatives  of,  255 
Ether,  317 

antidote  for,  587 

preparation  of,  318 

compound,  317 

properties  of,  320 

spirit  of,  321, 

spirit  compound,  321 

sulfuric,  320 

Williamson's    synthesis    of, 
318 
Ethereal  oil,  325 
Ethers,  table  of,  317 
Ethyl  acetate,  323 

alcohol,  274,  275 

aldehyd,  335 

benzene,  408,  41  7a 

benzoate,  484 

bromide,  257 

carbonate,  325 

chlorid,  256 
density  of,  576 

cyanid,  355,  376 

ether,  206 

iodid,  256,  323 

mercaptan,  342,  381 

naphthalene,  515 

nitrate,  375,  323 

phenylether,  452 

sulfate,  325 

sulfite,  373 

sulfonic  acid,  3S1 

toluenes,  417a 
Ethylamin,  442,  3  75 
Ethylene,  238,  239,  242 

series,  237 

diamin,  283 

glycol,  3S9 
Ethylene  oxids,  283 
Ethylidene  chlorid,  256 
Eucalyptol,  551 
Eugenol,        549,        551,        554, 

SS6 
Euphorbin,  512 
Euphorbium,  512 
Extraction  (vegetable),  40s 
Extracts  (perfume),  477 


6oo 


Factors,  187 

Fats,  291 

adulteration  of,  293 

analysis  of,  293,  294 

composition  of,  292 

liquid,  291 

preparation  of,  293 

properties  of,  293 

preservation,  294 

purification  of,  294 

solid,  292 
Fatty  acid,  series,  347 

acids,  table  of,  345 
Feathers,  469 
Fermentable  sugars,  398 
Fermentation  acetic,  267 

alcoholic,  267 
Fermentation  lactic,  268 

requisites  of,  270 

vinous,  267 
Ferments,  266,  267 
Fixed  oik.  292 
Fitiig's  reaction,  424,  429 
Fibers,  468 

animal,  468 

preparation  of,  468 

vegetable,  468,  469 
Flame,   Bunsen,  247 

gas,  246 

oxidizing,  246 

reducing,  246 
Floral  waters.  552 
Fluorin.  32 

compounds,  33 

properties  of,  32 
Fluorescein,  461 
Formaldehyd,  333 
Formic  acid  series,  347 
Forcite,  290 
Formose,  334 
Formulas,  chemical,  14,  182 

constitutional,  236 

empiric,  183,  236,  563 
calculation  of,  569 

graphic,  236 

molecular,  183,  236 

rational,  236,  571 

structural,  236 

type,  183 
Frankincense,  510 
Freezing-point,  method,  576 
Friedel  and  Crafts  reaction,  425 
Fruit  oils,  321 
Fructose,  394,  399 
Furfurol,  SS4 

Gadinine,  541 

Gas,  carburetting,  409 
composition  of,  409 
manufacture,  408,  409 
purification,  409 

Gaseous  state,  575 


Galactose,  394,  399,  400 
Galactozone,  399 
Galbanum,  511 
Gallalith,  334 
Gamboge,  511 
Gallic  acid,  471 
Garantose,  486 
Gelatin,  542 

blasting,  290 

explosive,  290 
General  formulas,  224 
Geranial,  549 
Geraniol,  548,  556 

acetate,  548,  556 

esters,  548 
Geranyl-acetate,  536 
Gin,  244 
Glass,  water,  47 

soluble,  47 
Glonoin,  289 
Glucose,  394,  397,  398 
Glucosid,  497 
Glucozone,  397 
Glusin,  486 
Glycols,  284 
Glycin-ammonia,  384 
Glycocol,  384 
Glycogen,  394,  403 
Glycollic  acid,  282 

aldehyd,  282 
Glyoxyl,  282 
Glyoxallic  acid,  282 
Glycerins,  285 
Glycerol,  285 
Glyceryl,  287 
Glycosids,  497 

nomenclature  of,  49? 
Glycosid,  497 
Goa  powder,  499 
Gold,  174 

Goulard's  extract,  354 
Granulose,  402 
Graphic  formulas,  231 
Graphite,  27 
Gray  lime,  341 
Green,  benzaldehyd,  464 

Brighton,  404 

Brunswick,  404 

malachite,  464 

mountain,  104 

Neuwieder,  104 

Paris,  103 

Scheele's,  104 

verdites,  104 
Grignard's  Reaction,  308 
Guaiacol,  456,  461 

carbonate,  457 
Guanidin,  392,  534 
Guanin.  391,  392,  393 
Guaranine,  534 
Gum,  chicle,  548 
Gums,  394,  S02 


6oi 


Gums,  natural,  504 

resins,  509 
Gun-cotton,  404 

soluble,  404 
Gutta-percha,  544,  548 
Gypsum,  135 

Halogens,  31 

hydracids,  32 

oxacids,  32 

oxids,  32 
Hartshorn,  162 
Hair,  469 
Hawthorn  oil,  47  7 
Heavy  oils,  407,  410 

spar,  132 
Headache     powders,    poisoning 

with,  58 
Helianthin,  428,  429 
Heliotropin,  478 
Hemellithine,  417a 
Hemlock  tannin,  496 
Henbane,  587 
Heptoses,  396 
Hesperidin,  545 
Heterocyclic,  527 
Hexahydroxycymene,  549 
Hexamethylene,  417 

tetramin,  417 
Hexamethylenetetramin,  332 
Hexamethyleneamin,  417 
Hexylene,  239 
Hexoses,  396 
Hoffman's  anodyne,  321 
Homatropin,  532 
Homologous  series,  184 
Homology,  214 
Holocain,  459 
Homocyclic  substance,  527 
Humulene,  547 
Hydracids,  16 
Hydroxylamin,  379,  396 
Hydrazin,  380,  444 
Hydrazins  substituted,  439 
Hydrazo  benzene,  446 
Hydroquinone,  460 
Hydrazin  benzene,  380 
Hydtazones,  380,  396,  397 
Hydrocarbons,    halogen   deriva- 
tives of,  258 

hydroxids  of.  260 
Hydrochloric    acid,   density   of, 

576 
Hydrocyanic      acid      poisoning. 
582 
antidote  for,  587 
Hydrocarbons,  211,  214 
properties  of,  216 
synthesis,  217 
Hydrocollidin,  541 
Hydroxy-aldehyd,  39s 
Hydroxy-anthroquinones,  522 


Hydroxy-benzene,  438 
Hydroxy-ketones,  395 
Hydroxy-napthalene,  515 
Hydroxy-toluenes,  434,  454 
Hydrolysis,  268 
Hydrogen,  18 

compounds,  18 

determination  of,  563 

preparation,  19 

properties,  18 
Hypnal,  339 
Hypnone,  479 
Hypo,  17 

Ichthyol,  453 

Idiosyncrasy,  579 
Imido  compounds,  387 
Immunity,  542 
Indium,  176 
Indigo,  463,  464,  468 

brown,  463 

synthesis,  463 
Indigotin,  463 

blue,  470 
Indicator,  567 
Indoxyl,  464 
Ink-blacks,  470 
Inorganic  and  organic,  7 
Invertase,  267 
Inulin,  394,  402 
lodol,  53  5 
Iodoform,  254 
lodin,  37 

antidote,  586 

number,  294 

preparation,  37 

poisoning,  582 

properties,  37 

solution  compound,  38 
lodism,  579 
Ion,  178 

Ionic  theory,  179 
Ion,  polarity  of,  179 
Irregular,  422 

Iron    and    ammonium  sulphate, 
115 

cast,  no 

chlorid,  114 

compounds,  112 

dialysed,  116 

distinction,  117 

ferrocyanid,  313 

hydroxid,  114 

with  magnesia,  115 

hypophosphite,  115 

liquor,  354 

pig,  no 

reduced,  112 

sulfate,  113 

tests,  116 

welded,  no 

wrought,  no 


6o2 


Iridium,  i7S 
Iso,  282 

Isoamylene,  241 
Isobutyrone,  340 
Isobutyronitril,  356 
Isocyanids,  376 
Isologous  series,  184 
Isomerism,  123,  23s,  421 
Isomeric,  206 
Isomorphous,  185 
Isonitroso  compounds,  380 
Isonitril,  439 
Isopentane,  233 
Isoprene,  554 
Isopropylcyanid,  356 
Isoquinolin,  530 

Jeaunel's  universal  antidote,  581 
ute,  469 

Kainite,  151 

Kauri  gum,  503 
Kekule's  theory,  414 
Ketone-diphenyl,  479 
Ketones,  211 

hydroxy,  391 

table  of,  340 

triose,  39S 

structure  of,  330 
Ketols,  342 
Ketoses,  395 

isomeric,  396 
Ketoximes,  331,  380 
Kolanine,  S3S 
Kolbe's  synthesis,  482 
KjeldahVs  method,  565.  s66 

Lactose,  394.  400 

Lactophenin,  459 
Lactone,  492 
Ladenburg's  prism,  41 S 
"Lager,"  272 
Lakes,  violet,  523 
brown,  523 

red,  523 

purple,  523 

orange,  523 
Lakes,  468 
Lampblack,  29 
Lanolin,  296 
Lanthanum,  176 
Lard,  294 
Laurin,  291 
Law  of  octaves,  109 
Lead,  82 

acetate,  354 

black,  27 

properties,  63 

toxicology  of.  83 

compounds,  84 

salts,  poisoning  with,  582 
antidote  for,  586 


Leather,  497 

chrome,  tanned,  497 
Leblanc's  process,  155 
Leucin,  385 
Leuco-base,  464 

indigotin,  470 
Levulose,  394-  398,  399 
Leukomains,  541 
Lignin,  403 
Light  oils,  407.  410 
Lignite,  28 
Linalool,  548 

esters,  548 
Linalal,  555 

Linalyl  acetate,  554.  55" 
Limonine,  545.  5 46 

hydrochlorids,  545 

tetrabrom,  545 
Lime  clays,  120 

stone,  135 

light,  136 

chlorinated,  137 

sulfurated,  137 

water,  137 
Liquor  chlori  compositus,  34 
Lithium,  141 

properties  of,  141 

compounds,  141.  142 
Litmus,  467 
Liver  of  sulfur,  151 
Lobeline,  531 
Logwood  black,  468 
Lye,  146 
Lydite,  4  54 
Lysol,  455 

Madder,  522 

Magenta  arsenate,  464 
Magnesia,  heavy,  167 

light.  166 
Magnetite,  109 
Magnesium,  166 

arabinate,  503  ..as 

Magnesium  compounds,  iO-^mOS 

tests  for,  168 
Maltose,  394.  40i 
Manganates,  127 
Manganese,  127 

black  oxid,  127 
hypophosphite,  128 
compounds,  128 
ores,  127 
sulfate,  128 
Manganite,  127 
Mannitol,  306 
Mannose,  394 
Margarin,  291 
Mass,  2 

Mastic,  503,  504 
Matter,  i 

aggregation,  2 
continuity  of,  2 


6o3 


Melitotriose,  394 
Mendelejeff's  classification.  170 
Menthyl  acetate,  556 
Menthol,  548,  S49.  55^ 
Menthone,  549 
Menthyl-monyl-ketone,  549 
Mercaptans,  380 
Mercaptids,  381 
Mercaptols,  342 
Mercerized  fiber,  404 
Mercurialism,  579 
Mercuric  chlorid,  105 
poisoning,  582 
antidote  for,  586 

compounds,  105,  107 

fulminate,  377 

iodid,  red,  106 

oxid,  red,  107 

thiocyanate,  379 
Mercury,  79 

black  oxid  of,  82 

chlorid,  mild,  81 

compounds,  81 

green  iodid,  81 

mild  chlorid,  81 

nitrate,  82 

preparation  of,  79 

properties  of,  79 

tests  for,  80 

toxicology  of,  80 

yellow  oxid,  81 
Mesitylene,  342,  408,  417,  433 
Mesitylic  acid,  433 
Metals,  8,  76 

atomic  weights  of,  178 

noble,  17s 

rare,  174 

refining  of,  181 

symbols  of,  178 

table  of,  176 

valences  of,  178 
Metalloids,  8 
Metamerism,  235 
Metaphenylene  diamin,  442 

position,  421 
Methane,  composition  of,  219 

derivatives  of,  248 

homologues  of,  227 
Methoxybenzoic  acid,  452 
Methyl-acetaniUd,  439 
Methyl -amin,  377,  382 

hydrochlorid,  387 
ammonium  bromid,  386 

anthracene,  408 

anthranilate,  454 

benzoate,  483,  484 

bismuth,  390 

cyanid,  376 

di-iodo  salicylate,  491 

di-oxytoluene,  446 

ethyl-benzene,  417a 
ether,  321 


Methyl-ester  of  amido-hydroxy- 
benzoic  acid,  491 

glycin,  385 

guanidin-acetic  acid,  385 
Methyl  isocyanid,  377 

mercaptan,  381 

mercury,  390 

naphthalin,  515 

nonyl-ketone,  ss6,  557 

orange,  429 

phenols,  454 

platinum  chlorid,  388 

salicylate,     324,     389,     492, 
554,  555 

sulfonic  acids,  381 

tin,  390 
Methylene-blue,  465 
Meyers'  Victor,  Method  of,  576 
Milk  of  hme,  137 
Mixtures,  9 
Molecule,  2 
Molecular  weight,  12 

determination,  571 

by  Avogadro's  law,  574 
Molybdenum,  175 
Monomorphous,  184 
Mordants,  464 
Morphine,  S33 

poisoning,  582 
antidote  for,  587 
Mortars,  120 
Mother  of  vinegar,  351 
Muriate  of  ammonia,  163 
Mushroom  poisoning,  582 
Mutton  suet,  294 
Mylitoxin,  541 
Myrcene,  556,  546 
Myristin,  291 
Myristicol,  556 
Myrobolans-tannin,  496 
My  rosin,  267 
Myrrh,  510 

Naphthalin,  408 

Naphthols,  516 
Naphthol  salicylate,  492 
Naphthyl,  516 
Naphthylamins,  517 
Naphthalin-sulfuric  acids,  517 
Naphthaquinones,  518 
Naphthalin     derivatives,      513, 

519 
Narcotine,  533 
Natural  gas,  220 
Neutral  principles,  497 
Neuridin,  541 
Neurin,  284,  541 
"Neutral  mixture,"  147 
Newland's  classification,  170 
Nicotine,  531 
Niccolite,  126 
Nickel,  126 


6o4 


Nigrosin,  468 
Niobium,  176 
Niobe  oil,  484 
Nirvanin,  491 
Nitrogen,  24 

determination  of,  5 "5 

in  organic  compounds,  37, 

preparation  of,  24 

properties  of,  24 

oxids,  25 
Nitrils,  307.  375 
Nitro-benzene,  374 

benzaldehyd,  meta,  470 
Nitrocellulose,  404 
Nitrocelluloses,  404 
Nitroderivatives,  37S 
Nitro-ethane,  37S 

glycerin,  289 

methane,  374 

naphthalins,  517 

paraffins,  3  74 
Nitrosamin,  439 
Nitroso-methylanilm,  439 
Nitrophenols,  453 
Nitrotoluene,  435 
Nobel's  oil,  289  .     ,      „ 

Nomenclature,  chemical,  182 
Nonmetals,  8,  18 
Nux  vomica,  534 

poisoning,  582 

antidote  for,  587 

Oak-tannin,  496 

Octoses,  396 

CEnanthone,  340 

Oil,  Dippel's,  515 

Oil  of  almonds,  bitter,  554 

anise,  554 

allspice,  556 

bay,  546,  556 

bergamot,  SS4 

birch,  325 

cade,  507,  554 

cajuput,  554 

cassia,  476 

caraway,  554 

cinnamon,  476,  555 

cloves,  554 

copaiba,  55  5 

coriander,  555 

cubeb,  555 

erigeron,  555 

eucalyptus,  55  5 

fennel,  555 

fleabane,  555 

gaultheria,  555 

garlic,  284 

juniper,  S55 

lavender,  ss^ 
flowers,  556 

lemon,  556 

lilac,  547 


Oil  o£  meadowsweet,  476 
mirrbane,  426 
mustard,  379.  557 
myristica,  556 
neroli,  554 
nutmeg,  ss6 
orange  flowers,  554 

peel,  554 
pennyroyal,  S5  5 
peppermint,  S5<> 
pimenta,  556 
roses,  556 
rosemary,  557 
rue,  557      , 
sandalwood,  55" 
sassafras,  557 
savin,  557 
spirea,  476 
spearmint,  556 
sweet  birch,  554 
syringa,  547 
tar,  507 
thyme,  557 
turpentine,  557 
valerian,  55  7 
wintergreen,  555 
synthetic,  324 
wormseed,  American,  556 
Oils,    volatile,    adulteration    of. 

difference  from  fixed,  550 

drying,  297 

essential,  549 

fish,  297 

intermediate,  297 

nondrying,  297 

oxygenated,  550 

sulfurated,  5  5° 

terpenes,  550      . 

volatile,  discussion,  549 
Olefin,  237 
Olefins,  table  of,  238 

properties  of,  239 

nomenclature  of,  242 
Olein,  291 
Oleo  oil,  296 
Oleomargarin,  295 
Oleoresins,  503,  504 
Olibanum,  510 
Optical  activity,  390 
Oppoponax,  su 
Opium,  538 

poisoning,  582 
antidote  for,  587 
Orcein,  467 
Orcin,  467 
Orcinol,  467 
Orchide^,  476 
Organic  analysis,  556,  5p3 

substances,  behavoir  witn 
immiscible  solvents,  SS9, 
561 


6o5 


Organic    compounds,    classifica- 
tion of,   211 

Organo-metallic  compounds, 

213.  389 
Ortho-position,  421 

dinitrobenzene,  442 

hydroxycinnamic   acid    lac- 
tone, 492 

phenylenediamin,  442 
Orthoform,  491 
Orphol,  S16 
Osazones,  380 
"  Ose,"  39S 
Oxacids,  17 
Oxalic  acid,  282,  586 
Oxalyl  group,  347 
Oxids,  acid,  22 

basic,  22 

neutral,  22 
Oxinies,  380,  398,  399 
Oxaldehyds,  476 
Oxyhydroquinone,  472 
Oxygen,  20 

determination  of,  569 

preparation  of,  21 

properties,  22 
Ozone,  23 

preparation  of,  23 

Palladium,  176 

Palmitin,  291 
Papayotase,  267 
Papaverine,  S33 
Paper,  406 

calendered,  406 

unsized,  406 

parchment,  404 
Para-acetphenetidin,  458 
Para-amidophenol,  458 
Paraldehyd.  535 
Para-nitrophenolethylether,    45S 
Para-phenetidin,  458 
Para  position,  421 
Para    rosanilin    hydrochlorid, 

46s 
Parchment  paper,  404 

vegetable,  403 
Paris  green,  103 

white,  138 
Paraffins,  iso,  234 

neo,  234 

nomenclature  of,  223 

normal,  234 

primary,  234 

secondary,  234 

table  of,  221 

tertiary,  234 
Pearl  ash,  145 
Peat,  28 
Pennsylvania    poison    law,   585 

588,  589 
Pental,  241 


Pentamethylenediamin      hydro- 
chlorid, 528 
Pentoses,  396,  472 
Pepsase,  266 
Peptone,  542 
Per,  17 

Periposition,  518 
Periodic  Law,  169 
Perkin's  reaction,  488 
Petroleum,  28,  222 

fractions  of,  223 

industry,  221 

theory  of  formation  of,  215 
Pharaoh's  serpents,  379 
Phellandrene,  544,  555,  556, 
Phenacetin,  458 

poisoning,  582 
Phenanthrene,  520,  525,  526 
Phenetol,  452 
Phenocoll,  4S9 
Phenol,  408,  438,  444 

alcohols,  473 

aldehyds,  476 

antidote  (same  as  Vegetable 
acids) 

ethers,  451 

derivatives,  452 

meta-dihydroxy,  460 

orthodihydroxy,  460 

paradihydroxy,  460 

sulfuric  acids,  432 
Phenols,   408,   449.  45° 

diatomic,  449.  460 

monatomic,  449 

nitric,  453 

triacid,  45° 

triatomic,  449.  47i 
Phenyl,  430 

acetate,  452 
Phenylamin,  435 
Phenyl  carbamid,  439 

cyanid,  440,  485 
P henylglucosazone,  397.  399 
Phenyl   hydrazin,  380,  396,  444. 
448 
hydrochlorid,  444.  445 

hydrazone,  331,  397 

hydrosulfid,  454 

isonitril,    439 

mercaptan,  454 

methane,  429 

methylether,  451 

methylketone,  478 

salicylate,  490 
Phloroglucinol,  471 
Phosgene,  359 
Phosphin,  388 

dimethyl,  388 

methyl,  388 

trimethyl,  388 
Phosphonium,  388.  389 

hydroxid,  389 


6o6 


Phosphonium,  tetramethyliodid, 

389 
Phosphorus,  42 

acids,  44 

antidote  for,  587 

compounds,  44 

determination  of,  569 

poisoning,  583 

preparation  of,  43 

properties  of,  43 
Phthalimid,  487 
Phthalic  acids,  487 

anhydrid, 487 
Physical  science,  s 
Physics,  5 

Physiologic  antagonists,  580 
Physostigma,   antidote   for,    587 
Physostigmine,  534 
Plaster  of  Paris,  139 
Platinum,  174 
Plumbago,  27 
Plumblism,  579 
Poirrier's  orange,  429 
Picolins,  529 
Picrotoxin,  497,  499,  501 
Pills,  enteric,  491 
Pinene,  544 
Pilocarpine,  534 
Piperidine,  528,  531 
Piperine,  531 
Piperonal,  478 
Podophyllotoxin,  497,  501 
Poison,  corrosive,  577 

cumulative,  578 

definition  of,  578 

irritant,  578 

law,  Pennsylvania,  585,  588 
589 

mechanic,  578 

true,  577 
Poisoning,  acute,  579 

chronic,  579 

methods  of  treating,  583 

ptomain,  582 

unknown,  treatment  of,  580 
Poisons,  antidotes  for,   586,   587 

effects  of,  578 

toxic  action  of,  578 
Pole,  negative,  178 

positive,  178 
Polymerism,  184,  235 
Polymorphous,  184 
Pomegranate  tannin,  496 
Porcelain,  120 
Porter,  274 
Potash,  146 
Potassium,  142 

benzoate,  484 

binoxalate,  364 

carbazole,  520 

compounds,  143,  151 

cyanate,  315,  378 


Potassium,  cyanid,  313 

ferricyanid,  312 

ferrocyanid,  148,  311 

hydroxid,  143 

hyi)ohosphite,  148 

iodid,  149 

permanganate,  128 

phenolate,  452 

preparation  of,  143 

properties  of,  143 

sulfobenzoate,  450 

sulfocyanid,  315 
Pottery,  120 
Prehnitine,  4173 
Propane,  228 
Propione,  340 
Propionitril,  376,  387 
Propionyl  chlorid,  371 
Propylamin,  387 
Propylene,  238 
Proteins,  212,  542 
Prussiate  of  potash,  yellow,  148 
Pseudocumene,    408,    417a 
Ptomain  poisoning,  582 
Ptomains,  538,  541 
Pulegone,  555 

Purification     of     organic  com- 
pounds, 558 
Purple  of  Cassius,  175 
Purpurin,  524,  525 

anthra,  524,  S2S 

flavo,  524,  525 
Putrefaction,  543 

table  of,  543 
Putrescin,  S4i 
Pyoktanin,  466 
Pyrazalone,  535 
Pyrazol,  535 
Pyrene,  407 
Pyridin,  408,  527,    528,    529 

derivatives,  531,  532 

tetramethyl,  541 

trimethyl,  541 
Pyridins,  dimethyl,  5^9 

methyl,  529 

trimethyl,  529 
Pyrocatechin,  460 
Pyrocatechol,  460 

dimonomethyl  carbonate, 
457 

methylene  ether  of,  55 1 
monomethyl,  45  7 
Pyrochromic  mixture,  355 
Pyrrol.  408 

derivatives  of,  S3S 
Pyrogallol,  470,  471 
Pyroxyllins,  404 

Quantivalence,  13 

Ounssi  metal,  161 
Ouaternary  phosphonium,  389 
(Juercitrin,  497,  501 


6o7 


Quick  lime,  136 
Quinidine,  533 
Quinine,  533 
Quinol,  460,  467 
Quinolin,  408,  529,  53° 

derivatives,  532,  533.  534 
Quinone,  467 
Quinones,  479- 
Roffinose,  394.  401 
Ramnose,  501 
Reaction,  6,  187 

Adamkiewicz  s,  542 
Biuret's  542 
Millon's  542 
xanthoproteic,  542 
Sandmeyer's,  485 
Reactive  bodies,  187 
Reagent,  187 
Rectification,  273 
Red,  Congo,  44  7 
liquor,  354 

prussiate  of  potash,  14a 
Turkey,  468 
Reimer's  synthesis,  476 
Rennin,  267 

Resin  of  guaiac,  503,  504 
Resins,  503 

balsamic,  503 
Resorcin,  460 

phthalin,  461 
Resorcinol,  460,  461 
Rhodamins,  462 
Rhodium,  176 
Rochelle  salts,  147 
Rosanilin,  440,  464.  47° 
Rosin,  S03 

soap,  547 
Rosolic  acid,  463 
Rubber,  S12,  548 

para,  512 
Rubidium,  177 
Rum,  274 
Ruthenium,  176 

Saccharids,  396 

Saccharin,  486 
Saccharoses,  394 

di,  394 

mono,  394.  390.  398 

poly,  394,  402 

tri,  394.  396 
Safrol,  SSI.  557 
Salacetol,  326 
Salacin,  497.  499.  474 
Sal  ammoniac,  163 
Salantol,  326 
Saleratus,  144 
Salicylal,  476 
Saligenin,  474 
SaHpyrin,  491 
Salol,  490 
Salophen,  491 

39 


Salt,  183 

of  sorrel,  364 
Saltpeter,  150 
Sal  tartar,  145 
Salts,  scale,  1 1  s 
Sal  volatile,  162 
Sandarac,  S03 
Sandmeyer's  reaction,  485 
Sanoform,  491 
Santalol,  S48,  557 
Santonin,  497.  499 
antidote  for,  587 
poisoning,  582 
Saponification,  332 

value,  294 
Sarcosin,  385 
Saturnism,  S79 
Scale  salts,  1 1 5 
Scammony,  511 

resin,  512 
Scandium,  176 
Scarlet,  Bieberich,  44  7 
Scopolamine,  532 
Seidlitz  powder,  148 
Seignette's  salt,  147 
Selenium,  47 
Shellac,  503 
"Side  chain,"  425 
Siderite,  109 
Silicon,  46 

compounds,  46 
Silk,  469 

artificial,  405 
Silver,  85 

compounds,  86,  88 
cyanid,  314 
isocyanid,  377 
nitrate,  antidote  for,  587 
poisoning,  583 
Sinigrin,  497 
Soaps,  preparation  of,  85 

hard,  288 
Soaps,  insoluble,  289 

soft,  288 
Soda,  151 

saleratus,  153 
Sodium,  151 

acetate,  152 
arsenate,  152 
benzoate,  153 
bicarbonate,  153 
bisulfite,  153 
Sodium  bromid,  154 

carbonate,  dried,  155 
monohydrated,  154 
chlorate,  156 
chlorid,  156 
citrate,  156 
dried,  152 
hydroxid,  151 
hypophosphite,  156 
ichthyosulfonic  acid,  453 


6o8 


Sodium  iodid,  157 

nitrite,  157 

nitrate,  157 

nitroethane,  375 

nitroprussid,  379 

orthoborate,  154 

oxalate,  364 

phenolate,  408,  489 

phenolsulfate,  158 

phenolsulfonate,  453 

phenylcarbonate,  489 

phosphate,  158 
dried,  159 

preparations,  159 

pyrophosphate,  159 

salicylate,  159,  489,  490 

sulfate,  160 

sulfite,  160 

sulfocarbolate,  453 

thiosulfate,  160 
Solids,  liquids  and  gases,  s 
Solution,  standard,  565,  .<;66 
Solvay's  process,  153 
Solvents,  558 
Sorbinose,  394 
Sorbitol,  306 
Sparteine,  531 
Spelter,  129 
Spiegeleisen,  11 1 
Spirit  of  nitrous  ether,  324 
Spirits,  Colonial,  265 

Columbian,  265 

Eagle,  263 

methylated,  265 
Standard  solution,  565,  566 
Starch,  394 
Steam,  density  of,  576 
Stearin,  291 
Stearoptenes,  551 
Steel.  1 10 

Bessemer,  1 10 

description  of,  112 

open-hearth,  it  i 

Siemens-Martin  process, 
III 
Stibin,  388 

trimethyl,  389 
Stibonium,  388 
Stimulants,  588 
Stoichiometry,  196 
Stoneware,  1 20 
Storax,  509 

Strammonium,  antidote  for,  s87 
Straw,  469 
Strontianite,  133 
Strontium.  133 

compounds,  134 

description  of.  134 

tests,  134 
Strophanthin,  497,  500 
Strychnine,  534 

antidote  for,  587 


Strychnine,  poisoning,  382 
Styrax,  509 
Sty  rone,  473 
Suberin,  406 
Substitution,  addition,  224 

of  acids,  383 

products,  220 
Succinamid,  36s 
Succinum,  504 
Sucrose,  400 
Sugar,  394 

cane,  394,  400 

fruit,  394 

grape,  394 

house  syrup,  400 

invert,  398 

malt,  394 

milk,  394,  401 

of  lead,  354 
Sulfonal,  343 
Sulfonic  acids,  381 
Sulfovinic  acid,  319 
Sulfonmethane,  343 
Sulfonmethylmethane,  343 
Sulfur  acids,  42 

alcohols,  380 

compounds,  42 

derivatives,  organic.  380 

determination  of,  569 

ethers,  382 

group,  39 

iodid,  41 

precipitated,  44 

preparation  of,  40 

properties  of,  40 
Sulfurated  potash,  151 
Sumach  tannin,  496 
Sylvite,  142 
Symbols,  11 
Symmetric,  421,  471 
Symptoms    suggesting    common 

poisons,  581,  582,  583 
Synaptase,  267 

Tan  liquor,  496,  497 

Tanning,  496 
Tannins,  494.  495 
Tantalum,  176 
Tar,  S07 

Tartar  emetic,  304 
Taurin,  284 
Tautomeric,  39s 
Tellurium,  47,  17s 
Tercbenc,  547 
Terebenthene,  545 
Terpcne,  408,  SSS.  Sh(>.  S.S7 
Terpenes,  544 

di.  544 

hemi,  544 

poly,  544.  548 

sesqui,  544.  546 
Tcrpinene,  547 


6o9 


Terpineol,  S47.  SSS.  SS7 
Terpin  hydrate,  547 
Terpinolene,  547 
Terra  alba,  139 
Tests  for  carbon,  561 

halogens,  562,  563 

hydrogen,  562,  563 

nitrogen,  561,  562 

phosphorus,  563 

sulfur,  563 
Tetrabromfluorescein,  462 
Tetronal,  344 
Tetroses,  396 
Thalium,  174 
Thebaine,  533 
Theine,  393.  534 
Theobromine,  393.  S3S 
Thiophene,  413 
Thiophenol,  4S4 
Thorium,  176 
Thymol,  457,  549.  557 
Tin,  96 

acids  of,  97 

oxids  of,  97 

preparation,  96 

properties  of,  96 

tests  for,  97 
Titration,  567 
Titanium,  176 
Titre,  56s 
Toluene,  429 

derivatives,  429 

metachlor,  431 

orthochlor,  431 

parachlor,  431 
Toluic  acids,  432,  486 
Toluidins,  440 
Toluol,  408,  417a,  459 

brom-,  424 
Toluyl  chlorid,  434 
Toxicology,  577 
Toxins,  541 
Tragacanth,  502 

Treatment  of  unknown   poison- 
ing, 580 
Tricarballylic  acid,  300 
Trichloraldehyd,  336 
Trichlorhydrin,  286 
Trihydroxyanthraquinone,  524 
Trimethylamin,  386,  387 
Trimethylaramonium  iodid,  388 
Trimethylbenzene,  342,  433 
Trimethylglycin,  38s 
Trimethylxanthin,  393 
Trimorphous,  184 
Trinitrin,  289 
Trinitrophenol,  454 
Trional,  343 
Triphenylmethane,  466 
Tfiphenylrosanilinhydrochlorid, 

46s 
Tristearin,  288 


Trypsase,  266 
Trypsin,  266 
Tungsten,  174 
Turkey  red,  468,  523 
Turpentine,  American,  545 

Canada,  506 

Chian,  506 

Cyprian,  506 

French,  545 

oil,  545 

Strassburg,  506 

Venice,  506 
Turpentines,  506 
Tyrotoxicon,  443 

Universal  antidote,  Jeaunel's  580 

Unknown   poisoning,    treatment 

of,  580 
Uranium,  176,  177 
Urate,  ammonium,  391 

lithium,  391 
Urea,  203,  360,  362,  391 

oxalyl,  391.  392 
Urethane,  325 
Uvitic  acid,  433 

Valence,  13,  I79 

of  elements,  186 

variable,  14 
Vanadium,  176 
Vanillin,  477,  478 

sugar,  478 
Vapor  density,  determination  of 

576 
Varnish  gums,  298 

manufacture,  298 
Veratrine,  534 
Veratrum,  antidote  for,  587 
•Ventilation,  63 
Verdigris,  103 
Vicinal,  471 

Victor  Meyer's  method,  576 
Vienna  lime,  144 
Vinegar,  351 

process,  quick,  352 
Violet,  crystal,  466 

methyl,  466 
Volatile    oils,     constituents    of, 
554,  557 

preparation  01,  552 

table  of,  554 
Volumetric  analysis,  566 

solution,  566 
Vulcanite,  512 
Vulcan  powder,  290 

Water,  48 

analysis,  57,  60 
•    atmospheric,  50 
ground,  52 
hard  (temporary),  52 
(permanent),  52 


6io 


Water,  lake,  53 

Xanthin,  391,  392 

mineral,  so,  S4 

derivatives  of,  S34 

ocean,  54 

dimethyl,  393 

pond,  53 

trimethyl,  393 

potable,  56 

Xylene,  424         ' 

rain,  51 

derivatives,  431 

river.  S3 

safe  and  dangerous.  57 

meta,  431 

ortho,  431 

spring,  SI 

para,  431 

steam,  48 

Xylenes,  431 

terrestrial,  so 

amido,  441 

well,  S2 

Xylenol,  408 

Waters,  floral,  SS2 

Xylidins,  441 

Wax,  bees',  297 

Xylitol,  :,o6 

Brazil-nut,  297 

Xylols,  408 

Chinese,  297 

myrtle,  297 

palm,  297 

spermaceti,  297 
Waxes,  297 
'Welsbach  burner,  247 

Yellow,  Martin's,  518 

naphthol,  518 

prussiate  of  potash,  14? 
Ytterbium,  176 
Yttrium,  176 

Whisky,  manufacture  of,  272 

Zinc,  129 

Whiting,  138 

Zinc  alloys,  131 

Wine-lee's,  ^02 

blend,  129 

Wines,  273 

compounds,  130,  131 

alcoholic      strength      of. 

dust,  129 

274 

ores,  129 

Witherite,  132 

salts,  antidote  for,  s76 

Wood,  destructive  distillation 

tests,  :3i 

of,  265 

toxicology  of,  131 

Wool,  468 

Zirconium,  176,  177 

fat,  296 

Zymase,  266 

2    OIO'^ 


f\    \Cp 


•% 


-■S*  /-  _ 


X 


